RB1 and prostate carcinoma: Additionally, a previous study suggested that the possible mechanism of KLF6-regulated cell apoptosis was by upregulating ATF3 expression in prostate cancer cells23, whereas the exact mechanism by which KLF6 regulates mitochondria-mediated apoptosis in WERI-Rb1 cells (whether directly caused by self-expression changes or indirectly via the regulation of downstream gene expression as a transcription factor) remains to be explored.