SIK1 and hepatocellular carcinoma: In particular, genes downstream of p38 MAPK including MAPKAPK2, NFkB2, p53, CHOP (DDIT3), MSK (RPS6KA4), CREB (ATF4), and c-Myc, were all upregulated, indicating activation of these signaling pathways in the HCC specimens (Figure 3).