Chadwick Boseman visited young patients at St. Jude Children's Research Hospital in 2018... as he waged his own private cancer battle

Fans of Chadwick Boseman were shocked to learn of his death Friday night after a four-years-long struggle with colon cancer.

St. Jude Childen's Research Hospital paid tribute to the actor, who died at age 43, with a tweet Saturday morning commemorating his 2018 visit with their young patients.

The Black Panther star spent time with some of the children even as he was in the midst of his own treatments for colon cancer, which he kept private until his death. 

Giving back: Chadwick Boseman, who died Friday at 43, delighted children at St. Jude Children's Research Hospital when he visited in 2018

'We are deeply saddened to hear of the passing of our friend Chadwick Boseman,' St. Jude wrote on Twitter.

'Two years ago, Chadwick visited the St. Jude campus and brought with him not only toys for our patients but also joy, courage and inspiration. Our thoughts are with his family and friends at this time.'

The hospital had previously tweeted about the visit in September 2018.

'It's not every day that St. Jude gets a visit from an Avenger! Thank you @ChadwickBoseman for stopping by to bring joy to our patients and learn more about our lifesaving mission!' 

Looking back: 'Two years ago, Chadwick visited the St. Jude campus and brought with him not only toys for our patients but also joy, courage and inspiration. Our thoughts are with his family and friends at this time,' St. Jude tweeted

Having a blast: The photos in the post showed Boseman dressed casually in a charcoal hoodie and track pants as he as he spent some time with kids, all of whom looked delighted to see him

The photos in the post showed Boseman dressed casually in a charcoal hoodie and track pants as he as he spent some time with kids, all of whom looked delighted to see him.

The Da 5 Bloods star beamed as he visited a little girl in her bed in one photo while showering her with Black Panther toys and Funko Pops, plus a cloud of confetti.

In another photo, he shared a laugh while another boy as he rested in bed.

Chadwick knelt down next to one child in a stroller wearing a Black Panther glove, and the two gave the now-iconic Wakanda salute salute together.

The South Carolina–born actor looked contemplative in a final photo as he gazed upward. 

Hero worship: Chadwick knelt down next to one child in a stroller wearing a Black Panther glove, and the two gave the now-iconic Wakanda salute salute together

Gone too soon: The South Carolina–born actor looked contemplative in a final photo as he gazed upward

The same year as his St. Jude visit, Boseman was moved to tears during a 2018 SiriusXM interview with Sway Calloway and his Black Panther cast members as he recounted meeting terminally ills fans excited for his superhero movie.

He recounted meeting 'two little kids,' Ian and Taylor, with whom he was staying in touch throughout the production of Black Panther, which was released in February 2018.

'What they said to me, and what their parents said, they're just trying to hold on until this movie comes,' he recounted. 

The Da 5 Bloods actor said that knowledge spurred him on to work harder on Black Panther. 

Heartbreaking: Boseman was featured in a recently resurfaced video from 2018 in which he tearfully recalled meeting two young fans with terminal cancer; shown in 2018

New fans: Boseman recounted meeting 'two little kids,' Ian and Taylor, with whom he was staying in touch throughout the production of Black Panther, which was released in 2018

Holding out hope: 'What they said to me, and what their parents said, they're just trying to hold on until this movie comes,' he recounted

'It’s a humbling experience because you’re like, "This can’t mean that much to them," you know?' he said. 'But seeing how the world has taken us on, seeing how the movement is, how it’s taken on a life of its own, I realized that they anticipated something great.'

Boseman was overcome with tears as he recalled that the two boys had both died before they were able to see the completed film.

'When I found out that they...' he began before let out a long sigh and pushing back from the microphone while his costars Lupita Nyong'o and Danai Gurira both tried to comfort him.

After along pause, he spoke again as tears rolled down his cheeks.

'Yeah, it means a lot,' he said, before the video cut out. 

Humbled: 'It’s a humbling experience because you’re like, "This can’t mean that much to them," you know?' he said. 'I realized that they anticipated something great'

Emotional: Boseman was overcome with tears as he recalled that the two boys had both died before they were able to see the completed film. 'Yeah, it means a lot,' he said through tears; still from Black Panther