To verify the protein expression levels of PRKCG, OSM, DPP4, LRRTM1, CXCL6, and CSF3R, 70 serum samples from 20 healthy controls (HCs) and 50 TAO patients (patient characteristics shown in Table 2) were collected to perform ELISA. Here, LRRTM1 is linked to thromboangiitis obliterans.