Will Cetuximab work if Kras codon 13 is mutated?

I have no idea what a "codon" is and the article is not easy to read but it is rather informative and hopefully helpful for Kras mutants  as it seems to suggest use of cetuximab and/or panitumumab

www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0055793

"...In summary,our data make sense in light of five recent studies which demonstrated that KRAS codon 13 mutations but not codon 12 mutations conferred benefit from cetuximab therapy in advanced colorectal cancer."