Examination of CSF-1R activation by Western blot. Western blot pictures (A.) and graph (B.) of the CSF-1R activation status in canine mammary carcinoma cell lines in control conditions (ctrl), in serum-starving conditions (−FBS) and in serum-starving conditions supplemented with CSF-1 (25 ng/ml) (−FBS/+CSF-1 25 ng/ml). The level of examined proteins was expressed as IOD (integrated optical density) of protein in arbitrary units with the value obtained using the Odyssey Infrared Imaging System (LI-COR Inc., USA). The results are expressed as the mean ±SD. The Tukey post-hoc test + ANOVA were applied (Graph Pad v. 5.0), the values differed significantly (p≤0.05) were marked as *, whereas values differed highly significant (p≤0.01 and p≤0.001) were marked as ** or ***, respectively.