Intriguingly, up to 24 genes (about 41% of the candidate DEGs) were cuticular protein encoding genes (GO:0042302 and GO:0005576), including CPR (cuticular protein with the R&R Consensus), CPG (glycine-rich cuticular protein), CPT (cuticular protein with a Tweedle motif) and CPH (hypothetical cuticular protein) genes, and 22 genes were uniquely up-regulated in the sml male sample (Table 2), suggesting that these cuticular protein genes may be related to melanism. Here, CPE is linked to freckles.