CD38 and B-cell chronic lymphocytic leukemia: Collectively, inhibitory CD38 studies using a patient derived Th-CLL cell co-culture strategy, alongside studies in CD38-and LGALS1 (galectin-1)-deficient malignant B cell lines, showed CD38-mediated CD45 activity regulation via CD43 expression and galectin-1 surface localization, while galectin-1 binding influenced co-localization of CD43 and CD45.