EGFR and osteosarcoma: The expression of epidermal growth factor receptors has been reported in several cancer types, including canine mammary carcinoma [25], gastric epithelial tumors [36], urothelial neoplasms [37,38], ovarian tumors [39], osteosarcoma [40], lung cancer [41], anal sac gland tumors [42] and feline mammary tumors [43,44], endometrial tumors [45], and pulmonary carcinoma [46].