We read with interest the report of Marin Kollef and coworkers1 on the usefulness of BAL soluble triggering receptor expressed on myeloid cells 1 (TREM-1) determination in diagnosing ventilator-associated pneumonia. We would like to warn the readers against an important methodologic aspect of the presented work: the authors used a commercially available assay, namely the TREM-1 Quantikine assay (R&D Systems; Minneapolis, MN), to measure soluble TREM-1 concentrations. It happens that this assay was recalled by R&D Systems during the early 2008 summer, and researchers informed (and even reimbursed) due to its inability to accurately measure soluble TREM-1 concentration. A new assay has just been lunched by this company. We therefore recommend to readers and researchers interested in this field to be very careful in interpreting data, positive or negative, obtained by the use of this very assay, and we would encourage the authors to perform new measurements with a different technique.