A kinase (PRKA) anchor protein 4 is a human gene encoded by the symbol, AKAP4. It may also be known as: A-kinase anchor protein 4; AKAP-4; A-kinase anchor protein 82 kDa; AKAP 82; hAKAP82; Major sperm fibrous sheath protein; Protein kinase A-anchoring protein 4; PRKA4; testis-specific gene HI; protein kinase A anchoring protein 4; cancer/testis antigen 99; A kinase (PRKA) anchor protein 4; AKAP82; CT99; FSC1; p82. The encoded protein has an amino acid length of 854 and a mass of 94.5 kDa. Other isoforms may exist. A kinase (PRKA) anchor protein 4 is a member of the AKAP110 family. Homologs of this gene exist in other organisms, including: Mouse, Rat.