CCND2 and cancer: Specifically, in addition to Ccnd2 encoding cyclin D2 which is particularly essential for self-renewal of B-1 cells (34), we identified that spermidine synthase (Srm) (35, 36), eukaryotic translation initiation factor 5A (eIF5a) (37), macrophage migration inhibitory factor (Mif) (38) and heat shock protein family A member 5 (Hspa5) (39) which have been reported to promote cell proliferation and survival or suppress apoptosis in lymphoid lineages and/or cancer cells, were upregulated in cluster 3 (Figure 4E).