PCNA and gastric cancer: The potential target network of CKI for the treatment of GC contained a total of 43 targets, sorted into CCND1, PIK3CA, PIK3CG, PIK3CD, AKT1, PIK3CB, CDKN1B, EGF, CDKN1A, CDK2, MAPK1, JUN, CDK4, PTEN, MTOR, RB1, MAPK8, FoxO1, CCNB1, FOS, PCNA, EGFR, FoxO3, NFKB1, CDK6, RPTOR, IKBKB, CCNA1, RPS6KB1, CCNA2, ERBB2, CDC6, CCND3, CCNE1, RAF1, MCM5, RICTOR, CCNB2, MMP2, MLST8, MMP14, TIMP2 and MSH6 according to the their degree value, and the degree of the first 21 targets is higher than the average.