KIT and breast carcinoma: There have been several studies regarding the c-kit expression of breast cancer, indicating that the c-kit expression decreased in breast cancer tissue whereas the normal epithelium of the mammary gland showed the c-kit expression (Natali et al, 1992a; Matsuda et al, 1993; Hines et al, 1995; Chui et al, 1996; Palmu et al, 2002; Tsuura et al, 2002; Ko et al, 2003; Simon et al, 2004; Ulivi et al, 2004; Yared et al, 2004).