Identification and characterization of the TTF-1/p63 double-positive cells from terminal respiratory unit of the human lung.Identification and characterization of the TTF-1/p63 double-positive cells from terminal respiratory unit of the human lung. ヒト肺終末呼吸ユニッにおけるTTF-1/p63共陽性細胞の同定とその特徴