Characterization of the different HEK 293T cell populations: Using a combination of lentivirus transductions and plasmid transfections, HEK 293T cells were modified to over-express DDR1, DDR1DN, DDR2, DDR2DN or both DDR1 and DDR2. (A) Over-expressions were analyzed by western blot using anti DDR1 (SCB), DDR2 (SCB), Myc (DDRDN) or GAPDH (loading control) antibodies. N = 3. (B) and (C), DDR1 (B) or DDR2 (C) in cell lysates were immunoprecipitated with the SCB antibodies. Protein autophosphorylations were analyzed using anti P-Tyr antibody (4G10), immunoprecipitation control was analyzed using anti DDR1 (B) or anti DDR2 (C) antibodies from SCB. N = 2.