MAP3K4 and cancer: In cancer cells and myocytes, evidence suggests that the induction of apoptosis by GADD45γ is dependent on p38 mitogen activated protein kinase (MAPK) or c-Jun N-terminal kinase (JNK) MAPK signaling pathways [2, 32], and that GADD45γ activates MAPK pathways via signaling cascades involving MTK1/ MEKK4 in response to environmental stresses [4, 33, 34].