MST1R and neoplasm: The incorporation of Sdc2, RON, and ABL1 into the receptor complex in tumor cells contrasts with the makeup of the complex in nontumorigenic cells; originally defined in HaCaT cells, Sdc4 immunoprecipitates contain EGFR and α6β4 and α3β1 integrins that the HaCaT cells use for migration on LN332 (7, 13).