Although biological roles of the Lck protein in cancer cells have not been fully confirmed, several lines of evidence suggest that this protein contributes to the process of neoplastic transformation (Marth et al, 1988; Robinson et al, 1996; McCracken et al, 1997; Krystal et al, 1998; Lutz et al, 1998). The gene discussed is LCK; the disease is cancer.