Activation of FPR by T20/DP178. The FPR-transfected rat basophil cell line ETFR was used to evaluate Ca²⁺mobilization induced by T20/DP178 (A) and cross-desensitization of cell signaling between T20/DP178 (1 μmol/L) and fMLP (100 nmol/L) (B). T20/DP178 did not induce Ca²⁺ in mock-transfected parental cells (C). (D) Induction of ETFR cell migration by T20/DP178 and fMLP. (E) T20/DP178 or fMLP did not induce significant migration of mock-transfected cells. (F) Displacement of ³H-fMLP binding to ETFR cells by T20/DP178.