Functions as a chaperone necessary for a stable expression of the CYBA and CYBB subunits of the cytochrome b-245 heterodimer (By similarity). Controls the phagocyte respiratory burst and is essential for innate immunity (PubMed:28351984). Interacts with CYBB; CYBC1 may act as a chaperone stabilizing Cytochrome b-245 heterodimer. Mutants are highly susceptible to Salmonella and Listeria infection and are impaired in their ability to control replication of either pathogen (PubMed:28351984). Mutant neutrophiles have a highly impaired superoxide burst (PubMed:28351984). Mice are very susceptible to Listeria monocytogenes and die within 5 days of infection, fail to form neutrophil extracellular traps but are resistant to melanoma metastasis (PubMed:28351984). Belongs to the CYBC1 family.