A, Schematic of experimental layout for measuring changes in protein secretion in conditioned media and gene expression in cardiac fibroblasts (CFs) cultured on hydrogels. B, Protein changes in select cytokines from cytokine array (normalized to 6 kPa condition, N=3, error bars show mean and SEM, 1‐way ANOVA, *P≤0.05, **P≤0.01). C, Schematic representation of experimental design to compare changes in cytokine gene expression in vitro with changes in vivo with isoproterenol (ISO). D, Changes in gene expression of cytokines from CFs cultured on hydrogels±TGFβ1 (transforming growth factor β 1) for 5 days (N=3, error bars show mean and SEM, 1‐way ANOVA, *P≤0.05, **P≤0.01, ***P≤0.001, ****P≤0.0001). E, Changes in gene expression of cytokines from CFs isolated from rats treated with vehicle or ISO (4 mg/kg per day for 3 days, N=6 for each group, error bars show mean and SEM, 2‐tailed unpaired T test, *P≤0.05, **P≤0.01, ****P≤0.0001). FC indicates fold change; IGFBP, insulin growth factor binding protein; OPG, osteoprotegerin; OPN, osteopontin; VEGF, vascular endothelial growth factor; and WISP‐1, Wnt1 inducible signaling pathway protein 1.