Low CD38-expressing lines showed a smaller Dara-induced ADCC, consistent with previous observations in MM and CLL cells where Dara-mediated cytotoxic effects correlated with the surface CD38 levels.24,35 Interestingly, we found that ATRA or Pom alone can raise surface CD38 on the PEL cell lines, particularly those with low CD38 levels. The gene discussed is CD38; the disease is B-cell chronic lymphocytic leukemia.