MAPK8 and cancer: After hybridization of the protein lysates of VA and PTPRG-expressing clones to the antibody array, dramatic reduction of phosphorylation of p38α-T180/Y182, CREB-S133, JNK-T183/185, T221/223, Akt-S473 and -T308, and c-jun-S63, was detected (Figure 1A and 1B), providing evidence to support a role for PTPRG as an Akt signaling regulator in cancer.