Pim-1 is a serine/threonine kinase that cooperates with c-Myc in lymphoid cell transformation. The expression of pim-1 increases during the progression from early to late G1, remaining high at the G1/S boundary and G2 phases of the cell cycle. Pim-1 is regulated at both the transcriptional and translational level, and it has been shown to be induced by IL-2 stimulation. Pim-1 also plays a role in T cell differentiation, and it has been shown to stimulate c-Myc-mediated apoptosis upstream of caspase-3-like proteases.