Occurs in almost all aerobically respiring organisms and serves to protect cells from the toxic effects of hydrogen peroxide. Promotes growth of cells including T-cells, B-cells, myeloid leukemia cells, melanoma cells, mastocytoma cells and normal and transformed fibroblast cells. 2 H2O2 = 2 H2O + O2 Homotetramer. The N-terminus is blocked. The disease is caused by variants affecting the gene represented in this entry. Belongs to the catalase family. Catalase entry