4F9, or CD82 molecule, is a human gene encoded by CD82. It may also be known as: CD82 antigen; C33 antigen; IA4; Inducible membrane protein R2; Metastasis suppressor Kangai-1; Suppressor of tumorigenicity 6 protein; Tetraspanin-27; Tspan-27; CD antigen CD82; suppression of tumorigenicity 6; R2 leukocyte antigen; C33; GR15; KAI1; SAR2; ST6; TSPAN27. The encoded protein has an amino acid length of 267 and a mass of 29.6 kDa. 4F9 is a member of the Tetraspanin (TM4SF) family. Homologs of this gene exist in other organisms, including: Mouse, Rat, Zebrafish, Frog, Chicken.