MAPK8 and cancer: Our study is not the first one that documents the important role of JNK signaling pathway in proliferation and cell cycle progression of malignant tumors as this issue was previously extensively studied in malignant tumors such as the ones showing inhibition of JNK reduces G2/M transit independent of p53, leading to endoreduplication, decreased proliferation and apoptosis in the cell lines of breast, lung, thyroid and cervical cancer21–24.