title: A new antigenic determinant for C4 of relatively low frequency.
mesh_terms: D000483:Alleles; D003181:Complement C4 / Q000235:genetics* / Q000276:immunology; D003168:Complement Fixation Tests; D000939:Epitopes / Q000235:genetics*; D005787:Gene Frequency; D006801:Humans; D010641:Phenotype
chemical_list: D003181:Complement C4; D000939:Epitopes