Complement Component 4b Deficiency, also known as c4b deficiency, is related to systemic lupus erythematosus and complement component 4a deficiency. An important gene associated with Complement Component 4b Deficiency is C4B (Complement C4B (Chido/Rodgers Blood Group)), and among its related pathways/superpathways are Complement cascade and Initial triggering of complement. Related phenotypes are recurrent otitis media and asthma