Bright field images of normal (A and B), patient-derived DMD (C and D), and KO DMD hiPSC-CMs (E and F) on flat or ANFS after two weeks of culture. Cells on flat substrata (A, C, and E) are randomly oriented while cells on ANFS (B, D, and F) have a more anisotropic and aligned structure. ANFS are oriented horizontally in the images. Scale bar: 100μm.