MAPK8 and neoplasm: In addition to enhancement of tumor progression, upregulated GSTP1 expression in TCC might also limit the efficacy of chemotherapeutic agents that act by inducing apoptosis via the JNK pathway (Wang et al., 2001; Townsend and Tew, 2003; Burg et al., 2006; Lo and Ali-Osman, 2007).