CXCL1 and atrial fibrillation: The clinical cohort of the present study was relatively small [29] AF patients and 16 controls), with initially limited baseline characteristics in the validation cohort; this small sample size precluded robust statistical analyses to explore correlations between CXCL1 levels and AF severity, progression, or phenotypic subtypes, potentially obscuring the biomarker potential of CXCL1.