ALK and neoplasm: The BEAS2B cells are not tumorigenic in nude mice, and in vivo injection of BEAS2B-Mer cells did not form tumor nodules while BEAS2B cells stably expressing EML4-ALK, a well-known transforming oncoprotein [20], did form subcutaneous xenografts (Supplementary Table 2), indicating a lack of transforming activity for Mer.