The one place on this site where genetics points at a choice between two treatments rather than at a dose — and even here the honest reading is narrower than the headline suggests.
The rare pharmacogenomic finding on this site that points at a choice rather than at a dose. CYP2A6 clears nicotine, and how fast a person clears it can be measured in blood as the nicotine metabolite ratio. In a randomised, double-blind trial that grouped smokers by that ratio before assigning treatment, faster metabolisers quit more successfully on varenicline than on the nicotine patch, while slower metabolisers did about as well on either (Lerman et al., Lancet Respiratory Medicine 2015). This is a stratified trial result, not a dosing guideline: no regulator requires the test, and both treatments work. What it argues against is treating the two as interchangeable.
Lerman C et al., Use of the nicotine metabolite ratio as a genetically informed biomarker of response to nicotine patch or varenicline for smoking cessation: a randomised, double-blind placebo-controlled trial. Lancet Respir Med 2015
These are the positions in your own file that carry the genes above. Not every gene in a guideline is one we report — where that is the case the gene appears above without a variant here, and the note says so.