Results .Implementation of Chemically Induced Chromosomal Interactions (CICI) . The method we developed, CICI, involves two existing techniques, chemically induced dimerization (CID)21 , 22and fluorescent repressor operator systems (FROS)23 , 24. In a commonly used CID system, FK506 binding protein (FKBP12) and the FKBP-rapamycin binding domain (FRB), two otherwise non-interacting factors, bind strongly in the presence of rapamycin25. We expressed LacI-FKBP12 and TetR...