CARMIL2 and smooth muscle tumor: In humans, biallelic CARMIL2 loss-of-function (LOF) variants cause a combined immunodeficiency, with susceptibility to viral, bacterial, mycobacterial, and fungal infections, immune dysregulation in the gut and skin (Schober et al., 2017; Wang et al., 2016; Magg et al., 2019), and a particular susceptibility to EBV+ smooth muscle tumors (EBV+ SMTs; Schober et al., 2017; Magg et al., 2018).