FOXM1 bound to the MuvB complex (consisting of LIN9, LIN37, LIN52, LIN54 and RBBP4) and MYBL2 (B-MYB) stimulates PLK1 transcription. This creates a positive feedback loop, where PLK1 phosphorylates and activates FOXM1 (Fu et al. 2008), while FOXM1 transcriptional activity results in increased PLK1 levels. MuvB and FOXM1 may persist on the PLK1 promoter throughout G2, while MYBL2 may gradually dissociate from the PLK1 promoter due to proteasome-mediated degradation initiated when MYBL2 is phosphorylated by CCNA (cyclin A)-associated CDKs (Sadasivam et al. 2012).