Transcription factor regulating the expression of cell cycle genes essential for DNA replication and mitosis (By similarity). Plays a role in the control of cell proliferation (By similarity). Also plays a role in DNA break repair, participating in the DNA damage checkpoint response (PubMed:17101782). Promotes transcription of PHB2 (By similarity). Expressed in fetal heart, brain, liver, lung, kidney and limb, but only in adult thymus. Appears to be expressed only in adult organs containing proliferating/cycling cells or in response to growth factors. Expressed at 14 dpc in the embryo. Phosphorylated in M (mitotic) phase. Phosphorylation by the checkpoint kinase CHEK2 in response to DNA damage increases the FOXM1 protein stability probably stimulating the transcription of genes involved in DNA repair. Phosphorylated by CDK1 in late S and G2 phases, creating docking sites for the POLO box domains of PLK1. Subsequently, PLK1 binds and phosphorylates FOXM1, leading to activation of transcriptional activity and subsequent enhanced expression of key mitotic regulators (By similarity). Truncated C-terminus.