Constitutively activation of signal transducers and activators of transcription 3 (STAT3) proteins are involved in multiple aberrant signaling pathway-oncogenic pathways, including pathways regulating tumor cell survival. STAT3 is one of the second messengers in the Janus activated family kinases/STAT signaling pathway and is regulated by many different factors involving tumorigenesis. Given that the activation of STAT3 is observed in nearly 50% of Lung cancers and more and more researches regarding STAT3 in tumors, here in, we reviewed the contribution of STAT3 to lung cancer growth and progression and then the context in which positive and negative regulation of STAT activation leading to cell competition provides a mechanism for therapeutic intervention for specific cancers is discussed.