EGFR and ulcer disease: First, to explore the differences in miR-126-3p, lncRNA XIST, and EGFR expression in rat skin tissues, we established a diabetic rat ulcer model, as shown in Fig. 1A. The blood glucose level of the diabetic ulcer group was substantially elevated relative to that of the normal group, as shown in Fig. 1B. Moreover, HE and Masson staining results showed that the skin structure of the normal rats had clear layers, the epidermis was uniformly thick and thin, the surface was mildly keratinized, the granular layer existed, and the structure of skin appendages in the dermis was normal.