PLN and cardiomyopathy: Although alterations in ER calcium handling are consistent with potential dysregulation of ER function—given the tightly regulated nature of ER calcium homeostasis and its critical role in protein folding, signaling, and induction of cell death (de Ridde et al., 2023; Mekahli et al., 2011)—the findings presented here do not fully explain the complex cardiomyopathy phenotype associated with the PLN-R14del mutation.