GAGE3 Background Information The GAGE family is comprised of a number of highly homologous acidic proteins involved in immunity and germ cell biology. Expressed most frequently in cancerous tissue, members of the GAGE family are considered potential targets for cancer immunotherapy. GAGE3 (G antigen 3), also known as CT4.3 (cancer/testis antigen family 4, member 3), is a 118 amino acid protein that belongs to the GAGE family and is expressed in a variety of tumor tissues. The only normal tissue expressing GAGE3 is testis. The gene encoding GAGE3 maps to human chromosome X, which consists of about 153 million base pairs and nearly 1,000 genes. The combination of a X and Y chromosome lead to normal male development, while two copies of X lead to normal female development. There are a number of conditions related to an unusual number and combination of sex chromosomes being inherited, including Turner's syndrome, Klinefelter's syndrome and Triple X syndrome. Color blindness, hemophilia, and Duchenne muscular dystrophy are well-known X chromosome-linked conditions that affect males more frequently as males carry a single X chromosome.
