BRCA1 and cyst: These genes participate at different levels, in the formation of the cyst chorion (e.g., SGEG and Arp-CBP), in the control of cellular division (e.g., BRCA1 and p8), or as molecular chaperones whose function is to avoid denaturation of the proteins (e.g., artemin, ArHsp21, ArHsp22, and p26).