Immunohistochemical Staining Protocol

IHC was performed as previously described [20 (link)]. Briefly, the slides were deparaffinised in xylene and rehydrated in graded ethanol. After incubation in 0.3% H₂O₂, antigen retrieval was performed in citrate buffer. Subsequently, sections were incubated with the primary antibody (Additional file 1: Table S1), horseradish peroxidase (HRP)-labeled secondary antibody (Gene Tech, Shanghai, China), stained with diaminobenzidine (DAB, Gene Tech, Shanghai, China), counterstained with hematoxylin, then, dehydrated in ethanol, cleared in xylene, and cover-slipped with resin. The integrated optical density (IOD) value was assessed by Image Pro Plus software (V 6.0).