PCNA and prion disease: There were 9 common KEGG pathways in the N-CC group (p < 0.01), namely, the cell cycle (PCNA, CDC25B, MCM3, MCM5, CDC6 [28], GSK3B, MCM6, CHEK2, PKMYT1, CDC20 [29], PTTG1, SMAD3, CCNB1 [30], RBL1, CDC7 [23], WEE1, CDK2 [31], CCNA2, and TTK), nucleotide excision repair, the Toll-like receptor signaling pathway, prion diseases, spliceosome, DNA replication, proteasome, colorectal cancer, and pancreatic cancer.