CS-6 inhibited tumor growth in lung cancer mouse models. An orthotopic mouse model of human NSCLC A549 was used to evaluate the effect of CS-6. Tumor volumes (A) and total weights (B) were measured. (C) H&E staining. (D). Immunohistochemical analysis of COX-2 and p-p65 protein expression in tumor samples. Neutral formalin fixed tumor samples were prepared from animals and analyzed by immunohistochemical staining with rabbit anti-rabbit second antibody using the Vectastain Elite ABC kit, and examined under a microscope.