The function of POC1A (POC1 centriolar protein A, Ensembl gene identifier ENSG00000164087) is as follows. Plays an important role in centriole assembly and/or stability and ciliogenesis. Involved in early steps of centriole duplication, as well as in the later steps of centriole length control. Acts in concert with POC1B to ensure centriole integrity and proper mitotic spindle formation. {ECO:0000269|PubMed:19109428, ECO:0000269|PubMed:23015594}.