"Panitumumab–FOLFOX4 Treatment and RAS Mutations in Colorectal Cancer" 
NEJM Sep 12
http://www.nejm.org/doi/full/10.1056/NEJMoa1305275?query=featured_home
"CONCLUSIONS

Additional RAS mutations predicted a lack of response in patients who received panitumumab–FOLFOX4. In patients who had metastatic colorectal cancer without RAS mutations, improvements in overall survival were observed with panitumumab–FOLFOX4 therapy. (Funded by Amgen and others; PRIME ClinicalTrials.gov number,NCT00364013.)"