A germinal center B cell that has the phenotype CD77-negative, IgD-negative, and CD38-positive. These cells have undergone somatic mutation of the B cell receptor. [ http://www.ncbi.nlm.nih.gov/pubmed/8006591 GOC:msz http://purl.obolibrary.org/obo/go/references/0000031 GOC:dsd http://www.ncbi.nlm.nih.gov/pubmed/18432934 ]

Synonyms: Bm4 B-lymphocyte Bm4 B lymphocyte Bm4 B-cell