Comparison of the relative resistance variations of all 4 VKAs among 27 naturally occurring VKOR mutations. The IC₅₀ of phenprocoumon (P), acenocoumarol (A), and fluindione (F) for all 27 VKOR mutations was determined, as described in the Figure 1 legend. The IC₅₀ of each VKA for wild-type VKOR was normalized to 1. The most resistant level among VKOR mutations of each VKA is indicated by a dotted line (also indicated by the fold increase) in the same color as their respective bar graphs.