CD4 and neoplasm: Visram et al. (42) evaluated bone marrow from 13 newly diagnosed, 11 relapsed pre-daratumumab, and 13 triple-refractory myeloma patients and found that patients who are resistant to three lines of therapy have a distinct immune tumor microenvironment including decreased CD4(+) T cells and naïve T cells compared to newly diagnosed and relapsed but pre-daratumumab treated patients.