Critical component of the membrane-bound oxidase of phagocytes that generates superoxide. It is the terminal component of a respiratory chain that transfers single electrons from cytoplasmic NADPH across the plasma membrane to molecular oxygen on the exterior. Also functions as a voltage-gated proton channel that mediates the H(+) currents of resting phagocytes. It participates in the regulation of cellular pH and is blocked by zinc. Composed of a heavy chain (beta) and a light chain (alpha). Component of an NADPH oxidase complex composed of a heterodimer formed by the membrane proteins CYBA and CYBB and the cytosolic subunits NCF1, NCF2 and NCF4. Interacts with NCF1. Interacts with calprotectin (S100A8/9). Interacts with NRROS; the interaction is direct and impairs formation of a stable NADPH oxidase complex (PubMed:19028840, PubMed:3600769, PubMed:9224653). Interacts with CYBC1; CYBC1 may act as a chaperone stabilizing Cytochrome b-245 heterodimer (PubMed:28351984). Interacts with NCF2; the interaction is enhanced in the presence of GBP7 (By similarity). The CYBA-CYBB complex interacts with GBP7 (By similarity). As unassembled monomer may localize to the endoplasmic reticulum. Detected in neutrophils (at protein level). Glycosylated. Phosphorylated on Ser and Thr residues. Undergoes 'Lys-48'-linked polyubiquitination, likely by RNF145, triggering endoplasmic reticulum-associated degradation. The disease is caused by variants affecting the gene represented in this entry. Disease susceptibility is associated with variants affecting the gene represented in this entry. Truncated N-terminus. CYBB deficiency database Leiden Open Variation Database (LOVD)