Knockdown of various epigenetic regulators influenced direct cardiac reprogramming. (a) Schematic of experimental design to determine the effect of candidate factors on iCM reprogramming via shRNA-mediated RNAi. FB stands for fibroblasts. (b) Knockdown efficiency of indicated shRNAs measured by RT-qPCR. Expression values were normalized to those measured in shNT-infected cells at reprogramming day 10. FC stands for fold change. (c) 25 selected chromatin modulators and splicing factors were knocked down in CFs coinfected with MGT for cardiac reprogramming. αMHC-GFP+ and cTnT+ cells were measured by flow cytometry at day 10 posttransduction. The percentage of marker positive cells was normalized to shNT-infected control cells shown in black. Bmi1 highlighted in red was used as a positive control for screening. (d) Histogram of normalized percentage of αMHC-GFP+ and cTnT+ cells after infection of MGT and shRNA lentiviruses targeting individual genes as indicated.