ABCA4 and atrial fibrillation: We found that 7 days after iron injection, the prevalence of hyperautofluorescent puncta in the SW-AF images was substantially increased in the FAC-injected Abca4–/– mice (Figure 2F) relative to both the FAC-injected wild-type mice (Figure 2A) and the saline-injected Abca4–/– mice (Figure 2F).