While there is still a way to go in designing personalized medicines, increasingly some interesting (and surprising) findings are unfolding. Indeed, it is becoming increasingly evident that gene mutations, changes in protein expression, or changes in the location of proteins in the cell can alter how the response to treatment. A recent study, presented at the American Association for Cancer Research Annual meeting, demonstrated that a mutation in KRAS, a gene commonly mutated in some cancer patients, reduces the responses to chemotherapy. This is, in and of itself, not welcomed news -- however, this study found that such KRAS mutations improve the response to anti-folate drugs (drugs not commonly used to treat lung cancer). Therefore, depending on the mutation present and the number of copies of that mutant protein that exist in the cell, anti-folate treatment may help stop cancer growth. The bigger picture that emerges from this study is that a mutation that is detrimental when common chemotherapies are employed, in fact, be quite beneficial when other therapies are considered.