highly significantp < 0.001
Using the Kruskal–Wallis test, we compared GC content across RNA types and genomic regions and found a highly significant global difference ( p < 0.001). circRNAs had the highest GC content, significantly exceeding that of mRNA coding sequences (CDSs). lncRNAs had relatively low GC content, significantly lower than mRNA CDSs and comparable to introns and intergenic regions (no significant pairwise differences).