The GOPC protein is localized at the trans-Golgi region of round spermatids, and the lack of this protein causes malformation of the acrosome.7 Protein interacting with C kinase 1 (PICK1) deficiency also causes male infertility in mice by disrupting acrosome formation.6 To determine whether the malformation of the acrosome in GM130-dificient germ cells is a result of the aberrant expression of these two proteins, immunostaining and western blot assays were performed. The gene discussed is GOPC; the disease is male infertility.