CDKN2A and neoplasm: Even though we observed weaker anti-tumor effects when using PTS than after direct CAP treatment, it is worthwhile to note that a significant induction of early apoptosis and the induction of Caspase-3, -7, -9, H2AX, p16 and p21 were observed after PTS treatment (Figure 7), whereas late apoptosis with cell death was not significantly induced in the present study (Figure 8).