VEGFA and dysplasia: 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).