Because CD49b marks neuronal progenitor cells in neural crest-derived lineages but is not expressed on differentiated neurons (Belkind-Gerson et al., 2015; Joseph et al., 2011; Morarach et al., 2021), we hypothesized that this antigen would distinguish immature and mature neuroblastoma cells. The gene discussed is ITGA2; the disease is neuroblastoma.