Reply to letter to Editor. (15th May 2020) - Yamamoto, Keiko; Nishimura, Rintaro; Kato, Fumiaki; Naito, Akira; Suda, Rika; Sekine, Ayumi; Jujo, Takayuki; Shigeta, Ayako; Sakao, Seiichiro; Tanabe, Nobuhiro; Tatsumi, Koichiro