Figure 1: Cultured aCFs showed a myofibroblast phenotype and distribution of Cx43 in cocultures of ESC-CMs with aCFs and MSCs. Cultured aCFs (a–d), ESC-CMs, and aCFs after coculture (e–h) and ESC-CMs and MSCs after coculture (i–l). Merged picture of the different channels (a, e, i) as well as α-smooth muscle actinin (b), sarcomeric α-actinin (f, j), vimentin (c, g, k), and Cx43 (d, h, l). Scale bars = 20 μm.