(56), using constitutively active STIM1 mutants selected from the cancer database and mutations associated with tubular aggregate myopathy (TAM) and live-cell recordings together with MD simulations, provided evidence that the hEF-hand and Phe108 play important roles in STIM1 activation by promoting dimerization while cEF and SAM retain their folded structure. Here, STIM1 is linked to transient myeloproliferative syndrome.