Finally, Src family kinases are known to be involved in STAT3 activation in lung cancer cell lines [28] and since the Src signaling pathway has been implicated in JSRV Env-induced transformation [13], [57], this may represent yet another pathway that could be responsible for STAT3 phosphorylation in JSRV Env-induced lung tumors. Here, STAT3 is linked to lung carcinoma.