A family history of recurrent infections of any type, but particularly viral (HPV caused warts in GATA2 deficiency), opportunistic infections [herpes zoster reactivation, primary CMV with retinitis/encephalitis, Pneumocystis jirovecii pneumonia, and Candida esophagitis in TBD (104, 107, 114)] or atypical bacterial (mycobacterial infections in GATA2 deficiency), may suggest the presence of concurrent immunodeficiency and should prompt a more careful laboratory evaluation. The gene discussed is GATA2; the disease is viral encephalitis.