KLF5 and Familial prostate cancer: We also used transient transfection of siRNAs to knock down KLF5 (Figure 5C) and adenoviral infection to transiently express KLF5 (Figure 5D) in the two prostate cancer cell lines, and confirmed that knockdown and overexpression of KLF5 respectively increased and decreased the expression of HIF1α (Figure 5C, D).