STAT3 and neoplasm: Luteolin activates SHP-1, a protein tyrosine phosphatase that dephosphorylates STAT3, and reduces the expression of its target genes, which “shut down” the regulation of target genes by inhibiting nuclear accumulation of STAT proteins, thereby demonstrating the efficacy of luteolin in inducing tumor growth inhibition in vivo (Song et al., 2017a).