MAPK1 and non-small cell lung carcinoma: Moreover, in a recent study, dealing with a potential anti-tumor agent (xanthohumol) inhibiting ERK activity and Fra-1 accumulation in NSCLC cells, Fra-1 deubiquitylation has been causally linked to the ERK-induced protein stabilization, as shown by the phosphomimetic mutation (S265D) causing the decreased polyubiquitylation and the increased half-life of Fra-1 [121].