Functions as a chaperone necessary for a stable expression of the CYBA and CYBB subunits of the cytochrome b-245 heterodimer (PubMed:30361506). Controls the phagocyte respiratory burst and is essential for innate immunity (By similarity). . This is the function of Ensembl gene identifier ENSG00000178927 (CYBC1, cytochrome b-245 chaperone 1).