The function of PI4KB (phosphatidylinositol 4-kinase beta, ENSG00000143393) is as follows. Phosphorylates phosphatidylinositol (PI) in the first committed step in the production of the second messenger inositol-1,4,5,-trisphosphate (PIP). May regulate Golgi disintegration/reorganization during mitosis, possibly via its phosphorylation. Involved in Golgi-to-plasma membrane trafficking (By similarity) (PubMed:10559940, PubMed:11277933, PubMed:12749687, PubMed:9405935). May play an important role in the inner ear development. {ECO:0000250|UniProtKB:O08561, ECO:0000269|PubMed:10559940, ECO:0000269|PubMed:11277933, ECO:0000269|PubMed:12749687, ECO:0000269|PubMed:33358777, ECO:0000269|PubMed:9405935}. (Microbial infection) Plays an essential role in Aichi virus RNA replication (PubMed:22124328, PubMed:22258260, PubMed:27989622). Recruited by ACBD3 at the viral replication sites (PubMed:22124328, PubMed:27989622). {ECO:0000269|PubMed:22124328, ECO:0000269|PubMed:22258260, ECO:0000269|PubMed:27989622}. (Microbial infection) Required for cellular spike-mediated entry of human coronavirus SARS-CoV. .