SRX is an alias for the gene, Sulfiredoxin 1, in humans. Other names include: Sulfiredoxin-1; Sulfiredoxin-1 ; C20orf139; Npn31. The encoded protein is an enzyme with an amino acid length of 137 and a mass of 14.3 kDa. Other isoforms may exist. SRX is a member of the Sulfiredoxin family. This gene shares homology with other species, including: Yeast.