CD15 is a carbohydrate antigen that features a typical trisaccharide arrangement involving 3-fucosyl-N-acetyl-lactosamine, and it’s also recognized as Lewis x (Lex) or the stage-specific embryonic antigen 1 (SSEA-1). 1-3 CD15 is found in myeloid cells, playing a role in the adherence of neutrophils to dendritic cells. 2-3 The presence of CD15 is noted in Reed-Sternberg cells, making it a valuable indicator for spotting Hodgkin’s lymphoma.