Although the rate of a positive c-kit expression varied in the different studies, the rate of a positive c-kit expression of benign tumours was always lower than that of normal breast tissue and the rate of a positive c-kit expression of the breast cancer was always lower than that of benign tumours in each study (Natali et al, 1992a; Tsuura et al, 2002; Yared et al, 2004). The gene discussed is KIT; the disease is breast carcinoma.