One review found that herpes zoster patients had twice the risk of stroke 4 weeks after zoster onset, but the risk of stroke returned to near-baseline levels after a year, whereas patients with recent CMV infection or reactivation (measured through immunoglobulin [Ig]M seropositivity) had over 5 times the risk of stroke compared to those without CMV IgM [10]. The gene discussed is CD40LG; the disease is herpes zoster.