CD47 and hepatocellular carcinoma: In the presence of cancer stem cells, 4MU downregulates the expression of CD47 on HCC cells and promotes phagocytosis of antigen presenting cells; in combination with adenovirus encoding interleukin-12 genes (AdIL-12), 4MU elicits a potent cytotoxic T-cell-specific response and prolongs survival in a hepatocellular carcinoma model established in fibrotic liver (93).