In contrast to germline gain-of-function Gα11 mutations, which affect Ca2+o homeostasis, somatic gain-of-function Gα11 mutations are reported to cause uveal melanoma, a primary intraocular tumour, by inducing constitutive upregulation of proliferative signalling involving extracellular signal-regulated kinases 1 and 2 (ERK1/2) (Van Raamsdonk et al. 2010), which are components of the MAPK signalling pathway. Here, MAPK3 is linked to uveal melanoma.