The functional ‘reorientation’ of myeloid cells is likely to be of pathogenic relevance in ALF, a condition that is characterised by systemic immune dysregulation, immuneparesis and a marked susceptibility to secondary infections.4, 11 Here, we also detect expanded numbers of MerTK+HLA-DR− cells, an immune cell subset with impaired innate responses to microbial challenge, during the evolution of human ALF. The gene discussed is MERTK; the disease is infection.