Ar-V7-IN-1 is a potent inhibitor of Ar-V7. Ar-V7-IN-1 inhibits the transcriptional activity of androgen receptor (AR) and the secretion of prostate-specific antigen (PSA) with an eGFP IC50 of 1232 nM and the PSA IC50 of 1391 μM. Ar-V7-IN-1 has the potential for the research of various indications, in particular cancers such as prostate cancer[1].