CD38 and lymphoma: In both lymphoma patients and HC, unsupervised cluster analysis showed that levels of naïve T cell populations correlated with the level of induced antibody responses (cluster 2, r = 0.6, p < 0.0001, cluster 11 (CD38+, ICOS+), r = 0.5, p = 0.01, and cluster 3, r = 0.3, p = 0.007) (Fig. 4D).