The MAPK pathway is an important pathway in the regulation of cell differentiation [40], although SPLUNC1 and truncated ΔSPLUNC1 had no effect on the total JNK1, p38, and ERK expression, it did clearly inhibit ERK phosphorylation and enhance JNK2 expression, leading to differentiation of NPC cells. The gene discussed is BPIFA1; the disease is nasopharyngeal carcinoma.