Mxd1 has been shown to be upregulated in murine bone marrow–derived macrophages upon initial infection with the hypervirulent Mtb HN878 strain (Roy et al. 2018) and to regulate the fitness of murine dendritic cells (Anderson et al. 2020), yet the function of Mxd1 in response to Mtb has yet to be determined. The gene discussed is MXD1; the disease is infection.