PTK2 and diabetic retinopathy: Scutellarin can reduce the expression of NF-κB, TNF-α, ERK1/2, reduce retinal damage caused by the activation of microglia during the development of diabetic retinopathy, and can also inhibit VEGF and its downstream protein p-ERK, phosphorylate focal adhesions Kinase (p-FAK), phosphorylated tyrosine protein kinase (p-Src), inhibits the angiogenesis of diabetic retinopathy by down-regulating vascular endothelial growth factor/ERK/FAK/Src pathway signals, and improves microvascular dysfunction (Mei et al., 2019).