From a story on theathletic.com by Jared Weiss headlined “How Marcus Smart’s support for cancer patients transformed children’s hospitals”:

Marcus Smart has spent far too much of his life sitting beside a hospital bed.

He endured years watching his brother Todd battle Leukemia when Marcus was in elementary school in Texas. He held his mother, Camellia, as she faced bone marrow cancer a few years ago. He is all too familiar with the last place most people want to be.
And yet, he keeps going back.