CASP3 and neoplasm: Immunohistochemical analysis of cleaved caspase 3 as a marker of apoptosis demonstrated very low levels (< 0.01% cleaved caspase 3-positive cells) in both Kin1-WT and Kin1−/− tumors, with no significant difference between the tumor types, suggesting that the increased growth of the Kin1−/− tumors was not due to decreased levels of apoptosis (Supplementary Fig. 2D).