Humphrey lost the battle to cancer at the Mulago based Uganda Cancer Institute.
Chameleone posted a picture of Humphrey on his Facebook page with only his name and a crying emoji.
His family had recently brought him back from the United States to get treatment close to home and surrounded by his people.
Humphrey Mayanja’s ailment was noticed in July last year, upon his arrival in the US from Uganda.
He was rushed to the hospital with severe stomach pain and underwent major surgery.
Early this month, his father Gerald Mayanja confirmed that his eldest son was being treated for stage-four colon cancer.
He said they decided to bring him back to Uganda to get treatment near home.