STAT3 and neoplasm: To determine the relation between TLR4 and STAT3 in melanoma in vivo, we established a pair of stable cell lines, A375CA-TLR4 (harbouring a constitutively active variant of TLR4) and A375NC (the negative control cell line harbouring the empty vector), then compared STAT3 activity in the two lines, and further compared tumor growth, angiogenesis and EMT in A375CA-TLR4- and A375NC-bearing mice.