The pioneer TRICC trial (Transfusion Requirements In Critical Care) by Hebert et al. including 838 critical care patients with normovolaemic anemia did not reveal any significant difference in terms of 30-day mortality between a restrictive transfusion strategy (single-unit transfusion to a transfusion threshold of 7.0 g/dL of Hb for a Hb target between 7.0 and 9.0 g/dL) and a liberal transfusion strategy (single-unit transfusion to a transfusion threshold of 10.0 g/dL of Hb for a target Hb between 10.0 and 12.0 g/dL) [7]. Here, GSTM1 is linked to anemia (phenotype).