To explore the higher expression of VEGFA in N and DN stage with ST feature plots and discover cellular interactions inferred by scRNA-seq, the epithelium of N and DN regions was separated into 2 parts under the guidance of pathology experts based on hyperkeratosis and dysplasia, the two identical characteristics of OLK separately initiating in the upper and lower layers of epithelium38 (Fig. 6c). Here, VEGFA is linked to Hyperkeratosis.