PARP1 and cancer: The cleavage of pro-caspases and PARP-1 in the PRMT5 knockdown A549-CFLARL cells was weaker than that in the control knockdown cells after treatment with doxorubicin, suggesting that CFLARL could prevent cancer cells from PRMT5-knockdown-enhanced apoptosis after doxorubicin treatment (Fig. 7A).