Audit MicroControls Inc, Eatonton, Ga, has added Linearity FD HE4, HER2 tumor marker calibrators to its line of calibration verification/linearity and daily quality control products. The product is intended to simulate human patient samples for the purpose of determining linearity, calibration verification, and verification of reportable range. The tumor marker calibrators consist of five levels that demonstrate a linear relationship to one another when assayed for HE4 and HER2. The product has an open-vial stability of 7 days when stored at 2–8°C. For more information, visit Audit MicroControls.