CDK1 and teratoma: However, the efficacy of purvalanol A for PSC-derived teratoma eradication (together with two CDK1 inhibitors, dinaciclib and Ro-3306) in another study showed that inhibiting CDK1 leads to the activation of the DNA damage response and negative regulation of the anti-apoptotic protein MCL1 in human and mouse ESC, but not in differentiated cells (72).