GC and colorectal cancer: Gene set enrichment analysis showed that one of the correlated groups was associated with negative regulation of keratinocyte differentiation (referred to as anti-epithelial genes) (P = 3.80 × 10− 3), whereas the other was associated with positive regulation of cGMP and guanylate cyclase (GC) activity (referred to as cGMP/GC genes) (P = 1.30 × 10− 3), which are known to be associated with negative regulation of β-catenin signaling and matrix metalloproteinase activity in colorectal cancer [27, 28].