Increased catabolic efficiency of the minor CYP26B1 variant. Purified minor (open circles) and major (filled squares) rs2241057 CYP26B1 variants were introduced in a cell-free system. [3H]atRA was added and its concentration was measured over time using HPLC. Open diamonds show levels in the absence of CYP26B1. The horizontal dashed line indicates baseline concentration. Values are mean ± SEM. dpm, disintegrations per minute. ***P < 0.001.