(A) Comprehensive genetic cluster analysis of ADFs and NCFs. (B) Expression levels of the VCAM-1 gene in NCFs and ADFs as measured by real-time PCR (N = 3, *P < 0.05). (C) VCAM-1 protein expression levels in conditioned medium of NCFs and ADFs as measured by enzyme-linked Immunosorbent assay (ELISA) (N = 4, **P < 0.01). (D) Immunocytochemical imaging of VCAM-1 co-receptor integrin α4β1 surface expression by mESC-derived cardiomyocytes; cTnT (green), integrin α4β1 (red), and Hoechst 33258 (blue nuclei), Scale bar = 500 μm. (E–F) Effect of neutralizing antibodies on cardiomyocyte number on Day 5 in two-chamber culture; YFP (green), cTnT (red), and Hoechst 33258 (blue nuclei). Scale bar = 500 μm, N = 3, **P < 0.01. (G–H) Effect of VCAM-1 (soluble protein) on cardiomyocyte number on Day 5; YFP (green), cTnT (red), and Hoechst33258 (blue nuclei). Scale bar = 500 μm (N = 3, *P < 0.05, **P < 0.01).