c-Src tyrosine kinase can constitutively activate STAT3, which increases the possibility of the STAT signaling pathway regulating tumor-related gene expression.155 Epidermal growth factor receptor can directly activate STAT1, STAT3, and STAT5, furthermore, STAT5 can be directly activated by the platelet-derived growth factor receptor.99,156,157. This evidence concerns the gene STAT1 and neoplasm.