dFKBP-1 potently decreases FKBP12 abundance in MV4;11 cells, leading to over 80% reduction of FKBP12 at 0.1 μM and 50% reduction at 0.01 μM. As with dBET1, destabilization of FKBP12 by dFKBP-1 is rescued by pre-treatment with Carfilzomib, MLN4924, free SLF or free Thalidomide. Cereblon (CRBN)-dependent degradation is established using previously published isogenic 293FT cell lines which are wild-type (293FT-WT) or deficient (293FT-CRBN?/?) for CRBN. Treatment of 293FT-WT cells with dFKBP-1 induces potent, dose-dependent degradation of FKBP12, whereas 293FT-CRBN?/? are unaffected[1].