Anti-P-Y15-cdk1, MPM-2 and Flag antibodies were from Cell Signaling Technologies (Danvers, MA, USA), Merck Millipore (Billerica, MA, USA) and Sigma-Aldrich respectively. Anti-Fcp1 antibodies were from Bethyl Laboratories (Montgomery, TX, USA) and Santa Cruz Biotechnology (Dallas, TX, USA). Rabbit polyclonal antibodies against P-T239 of human Wee1 were previously described.10 (link) Other antibodies were from Santa Cruz Biotechnology. Immunoprecipitations and immunoblots were performed as described.10 (link) Densitometric quantitations of immunoblot signal intensity were performed by using the ImageJ software (National Institutes of Health, Bethesda, MD, USA).