MAPK8 and neoplasm: Furthermore, although we hypothesized that progenitor state markers might be increased within the tumors if JNK signaling was promoting their expression to maintain tumor overgrowth, the expression array data indicated that hth, tsh, ey, toy and optix expression were either not significantly altered, or were downregulated, in both Ras and Notch-driven tumors compared to control eye-antennal discs.