PLN and Hyperglycemia: Notably, the expression of ALN in HEK293T cells impaired intracellular Ca2+ release upon stimulation with thapsigargin (Figure S6M), which was diminished even further after the expression of a phosphorylation-deficient (ALN S19A) but not by a phosphomimetic (ALN S19D) ALN mutant43 (Figure S6M), suggesting that, similar to PLN, dephosphorylated ALN might also contribute to the inhibition of SERCA at hyperglycemia.