CXCR5 and pachyonychia congenita: Based on antibody microarray analysis, the molecular mechanisms of the CXCL13/CXCR5 axis participating in PC cell proliferation and motility mainly include the PI3K/Akt/cyclin-dependent kinases (Cdk)1/2-Cdk inhibitor 1B (CDKN1B), stress-activated protein kinase (SAPK)/c-Jun kinase (JNK), Src/Erk1/2, and integrin β3-FAK/Src-Paxillin (PXN) pathways [73,100,101,140].