Immediate-early gene. Plays an important role in embryonic development as well as in cellular growth and proliferation; its long-term silencing affects cell survival and cell cycle distribution as well as decreases CDK1 activity correlated with reduced phosphorylation of CDK1. Plays a role as a positive regulator of the sonic hedgehog pathway, acting downstream of PTCH1 (PubMed:16024801, PubMed:9372240). Plays an important role in the regulation of centriole duplication. Required for the onset of procentriole formation and proper mitotic progression. During procentriole formation, is essential for the correct loading of SASS6 and CENPJ to the base of the procentriole to initiate procentriole assembly (PubMed:22020124). In complex with STIL acts as a modulator of PLK4-driven cytoskeletal rearrangements and directional cell motility (PubMed:29712910, PubMed:32107292).