MAPK3 and cancer: In the nucleus, DUSP5 not only inactivates ERK1/2 but also anchors ERK1/2, which was reported to paradoxically enhance cytoplasmic ERK activity in cancer via reduced ERK‐mediated RAF inhibition (Bellou et al., 2009; Kidger & Keyse, 2016; Kidger et al., 2017).