CSF1R and lung cancer: Lastly, the effect of knocking-down CSF-1R on the clonogenicity of the lung cancer cells was partially rescued by transfecting H1299 and H1975 cells with an expression vector coding for a ligand independent, constitutively active CSF-1R receptor, the CSF-1R L301S/Y969F [52, 53] (Supplemantary Figure S2B).