SPP1 and non-small cell lung carcinoma: Rationale: Transmembrane 4 superfamily member 4 (TM4SF4) has been identified as a key regulator of epithelial-mesenchymal transition (EMT)-associated stemness in non-small cell lung cancer (NSCLC) cells through autocrine signaling involving insulin-like growth factor 1 (IGF1) and osteopontin (OPN).