We constructed gene network using pairs in AIGPS-20 identified after RMA+norm for 5-class, 3- class, and 2-class (Figures 6B, S14A and S14B), and discovered key genes as skin cancer biomarker, such as HSD11B1, SLC45A2, KRT20, etc. By performing gene enrichment analysis using genes in AIGPS-20, we found that these genes are predominantly associated with cancer and gene regulation (Figures 6C, S14C, and S14D). The gene discussed is KRT20; the disease is cancer.