Western blot gels for the two EGFR antibodies and the COX-2 antibody. A. Two bands were detected with the COX-2 antibody, at approximately 66 kDa and 74 kDa. The antibody against the extracellular part of EGFR detected bands of different size. These bands are probably the different isoforms of EGFR. (STD = standard protein, M = mucosa, T = tumor). B. EGFR samples were separated in a Nupage Tris-Acetate gel for improved molecular weight separation. Molecular weight of proteins (kDa) was estimated from prestained molecular markers. Samples were randomly selected.