STIM1 and transient myeloproliferative syndrome: STIM1 and ORAI1 gain-of-function (GoF) mutations induce SOCE overactivity and excessive Ca2+ influx, leading to tubular aggregate myopathy (TAM) and Stormorken syndrome (STRMK), two overlapping disorders characterized by muscle weakness and a variable occurrence of multi-systemic anomalies affecting spleen, skin, and platelets.