CYCS and colorectal carcinoma: In the current study, qRT-PCR was used to examine the mRNA expression levels of the main regulators of apoptosis, including caspase9, Bax, and Bcl2. In CRC cells, STAT6 knockdown and 5-FU treatment promoted mitochondrial cytochrome C release, suppressed Bcl2 expression, and up-regulated Bax and caspase9 expression as a proapoptotic regulator.