Comparison of expression of genes encoding proteins important for Ca2+ cycling in cardiomyocytes (IP3R, RyR, SERCA2a, CASQ2, CALR, JPH2, PLN, Cav3.1, Cav1.2, NCX and TRDN) when normalised to GAPDH and expressed relative to adult heart tissue in iPSC-CM cultured on structured and control substrate, fibroblasts, adult heart and foetal heart tissue.