To confirm the endogenous interaction between miR-31–5p and CALCR (i.e., occupancy of miR-31–5p on CALCR-3’UTR) we assessed, with previously validated RNA-binding protein immunoprecipitation (RIP) assay and qPCR (16), the loading of both targets into the RNA-Induced-Silencing-Complex (RISC) in AF-ACFs. This evidence concerns the gene CALCR and atrial fibrillation.