Ferrater et al. (2015) found that BPH populations from six sites in the Philippines adapted to IR62 (BPH3 and/or BPH32) and IR65482-4-136-2-2 (BPH10) within 12–15 generations, but the polygenic variety PTB33 (BPH2, BPH3 and/or BPH32, and ZLH3) remained resistant for over 20 generations. Similarly, Hirae et al. (2007) found that GRH failed to establish and adapt to Norin-PL5 (GRH2 and GRH4) and Norin-PL6 (GRH2 and GRH4), whereas populations virulent against the monogenic line Kanto-PL6 could be selected within five to eight generations. The gene discussed is GNRH1; the disease is benign prostatic hyperplasia.