It is an immunoglobulin(Ig)G2 antibody that binds to the extracellular portion of the EGFR thusinhibiting phosphorylation and activation of the intracellular kinases [41].Efficacy of panitumumab has been evaluated in EGFR-expressing metastaticcolorectal adenocarcinomas with disease progression following oxaliplatin,irinotecan, and fluropyrimidine-containing chemotherapy regimens. This evidence concerns the gene EGFR and adenocarcinoma.