The purpose of this study was to evaluate the transplantation of BCC to the C57/BALB/C bgJ/bgJ-nu/nu (beige-nude) mouse. This animal has two gene defects which are expressed as impairment of natural killer cells (NK cells) as well as the absence of a thymus. The results demonstrate that human BCC can be successfully transplanted to the C57 beige-nude mouse without the need for supplemental immunosuppression. It may be that the impairment of NK cell activity in the beige-nude mouse model plays a significant role in tumor transplantation.