SAMHD1 summary. (A) Metabolic pathway of nucleoside analogs. (B) SAMHD1 gene schematic with top 3 SNPs. CDA, cytidine deaminase; CMPK1, cytidine monophosphate kinase 1; DCK, deoxycytidine kinase; DCTD, deoxycytidylate deaminase; hENT1, human equilibrative nucleoside transporter (hENT1/SLC29A1); NDPK, nucleoside diphosphate kinases; NT5C2, 5′nucleotidase; RRM1/RRM2, ribonucleotide reductase catalytic subunit M1/M2; SAMHD1, SAM domain and HD domain 1; GTEx, Genotype-Tissue Expression project; WT, wild type.