COL6A1 and atrial fibrillation: Fibrotic-related genes including ACTN1, COL6A1, MFGE8, IGFBP7, EN1, SPARC, MAP1B, EDIL3, TPM1, COL6A2, and BGN were highly expressed in fibroblast cells and myofibroblasts in the AF group (Figure S6C).