A) Troponin C (TNNC) expression of day 14 hiPSC-CMs differentiated with the addition of NODAL inhibitor SB431542 (SB) ranging from 0.2 to 20 μM with and without WNT inhibitor, IWR1, on differentiation day 3–5 normalized to the IWR1 only control (n = 3). B) Troponin T (TNNT2) transcript of day 20 hiPSC-CMs differentiated with the addition of NODAL inhibitor SB during mesodermal (Meso), cardiac mesodermal (C. Meso), and cardiac progenitor cell (CPCs) stages with and without IWR1. All experimental conditions were normalized to the control with no small molecule. Two hiPSC lines, iPS-DF19-9-7T and iPS-DF6-9-9T, were tested (n = 3). * denotes p < 0.05.