In our study, it was planned to determine whether administration of tamoxifen would induce Cre-loxP recombination and a mosaic pattern of SW-AF in female heterozygous mice; however, it caught our attention in IHC staining that tdTomato-positive cone cells could not be labelled by anti-ARR3 antibody, perhaps because the antigen was modified by 2A peptides. Here, ARR3 is linked to atrial fibrillation.