MAPK8 and neoplasm: Similar cell cycle arrest has also been observed in wholly scrib–/– wing imaginal disc tumours – strong JNK signalling in periphery cells early in tumourigenesis induces G2/M phase arrest, but JNK signalling decreases over time in these cells and, together with a concomitant increase in Ras-MAPK signalling, the cell cycle arrest ceases and the tumours overgrow (Ji et al., 2019).