PPIB and benign prostatic hyperplasia: The Cyt-b5-r group in BPH (Nlug-Cytb5r) possesses a single-copy gene, and clustered with the Cyt-b5-r genes in Acyrthosiphon pisum (Acpi-Cytb5r-a and Acpi-Cytb5r-b) and Bombyx mori (Bmor-Cytb5r-b) (Figure S1).