HIF-1α knock-down also enhanced the levels of apoptotic markers such as cleaved-PARP, cleaved-caspase 3 and cleaved-caspase 9 and reduced the Mcl-1 protein level in IMQ-treated BCC and SCC12 cells (Fig. 5B and Fig. S5). This evidence concerns the gene CASP3 and skin basal cell carcinoma.