STIM1 R304 is located in a coiled-coil domain of STIM1, and human patients with substitution of the arginine at residue 304 by tryptophan (STIM1-R304W, a constitutively active form of STIM1) show Stormorken syndrome, which is a multisystemic disease characterized by skeletal muscle phenotypes, including tubular aggregate myopathy, muscle spasms, muscle weakness, atrophy, lack of endurance, and hematological phenotypes [5,9,10,11]. This evidence concerns the gene STIM1 and Stormorken-Sjaastad-Langslet syndrome.