circRNA structures per gene. (A) Histograms showing circRNA numbers per gene established using PTESFinder for RBCs (this study), platelets,¹¹  fibroblasts, and fibroblasts digested with RNAse R.²³  (B) Schematic diagram showing XPO1 intron/exon organization with read counts and inferred structure of all circRNAs identified within the 3 platelet samples. Inferred structures assume that all internal Refseq exons are present within the structure defined by each back-splice. Read counts for the 11 structures identified previously within RNAse R digested H9 ES cells²⁷  are highlighted in red.