COPS5 and gastric cancer: A correlation was also detected between CSN5 levelS of CSN5 and the differentiation degree in GC (OR = 4.96, 95% CI: 2.02–12.19, p = 0.0005), CRC (OR = 2.58, 95% CI: 1.21–5.51, p = 0.01) and ESCC (OR = 2.08, 95% CI: 1.37–3.15, p = 0.0005).