Pre-clinically, tasquinimod produced a robust inhibition of prostate cancer growth in vivo in a range of phenotypes and genotypes most characteristic of clinical tumours from patients with localised or metastatic, androgen receptor (AR)-positive or AR-negative, AR wild-type or mutant, as well as prostate-specific antigen (PSA)-positive or PSA-negative cancers. The gene discussed is AR; the disease is prostate cancer.