Cytochrome b (-245) is composed of cytochrome b alpha (CYBA) and beta (CYBB) chain. It has been proposed as a primary component of the microbicidal oxidase system of phagocytes. CYBB deficiency is one of five described biochemical defects associated with chronic granulomatous disease (CGD). In this disorder, there is decreased activity of phagocyte NADPH oxidase; neutrophils are able to phagocytize bacteria but cannot kill them in the phagocytic vacuoles. The cause of the killing defect is an inability to increase the cell's respiration and consequent failure to deliver activated oxygen into the phagocytic vacuole. [provided by RefSeq, Jul 2008]
Forensic Context
A study in mice demonstrated that the CYBB gene, a reactive oxygen species-associated marker, was significantly increased in female microglia compared to male microglia after spinal cord injury, and was also increased in 14-month-old microglia compared to 4-month-old microglia, with expression higher in monocyte-derived macrophages than in microglia [Stewart et al. DOI:10.1186/s12974-021-02161-8]. In a rat model of radiation-induced lung injury, single-cell transcriptomic analysis identified the orthologous rat gene for the CYBB as being associated with inflammatory processes [Shi et al. DOI:10.17305/bb.2024.10357].