WNK2 and cancer: Moreover, signaling pathways such as negative regulation of apoptosis and the mitogen-activated protein kinase (MAPK) pathway which are known to be up-regulated in cancer and to play a central anti-apoptotic role in tumor progression, were found to be downregulated in process 1 in Hi, Pu, and CN brain regions (Table S2; tab “process 1 G1 > 0.01”), in accordance with their reported role in learning and memory formation [37].