PRG4 and atrial fibrillation: Using SYBPR‐based qPCR to assess the expression of extracellular matrix (ECM) genes, ECM‐remodeling genes, candidate mechano‐sensitive genes, inflammatory cytokines and cell surface receptors, we demonstrated that exposure of AF cells to CTS at 0.1 Hz increased Acan, Prg4, Col1a1 and Mmp3 expression.