HLA-C and irritable bowel syndrome: Two traditional Chinese medicines, Phellodendri Amurensis Cortex (PAC) and Achyranthis Bidentatae Radix (ABR), showed potential in treating IBS, possibly through active compounds like quercetin, berberine, and evodiamine, targeting proteins Tumor Protein p53 (TP53), 5′(3′)-Deoxyribonuclease (NT5E), Jun Proto-Oncogene (JUN), and major histocompatibility complex (MHC), Class II Invariant Chain (CD74).