FSCN1 and breast neoplasm: Recent evidence suggests that aberrant STAT3 signaling accelerates the growth of breast tumors by downregulating the expression of downstream target genes that regulate angiogenesis, such as hypoxia-inducible factor-1 (HIF-1) and nuclear factor-kappaB (NF-κB), and by binding to the promoter of the FSCN1 gene, triggering its expression [23].