SAMHD1 and Aicardi-Goutieres syndrome: Notably, the undetectable type I IFN protein in the sera from SAMHD1-deficient mice[12] did not mirror the elevated levels of serum IFNα found in some human AGS patients[3,11], suggesting that SAMHD1 deficiency in mice is not sufficient to enhance the production or release of type I IFNs.