Only one other tumor sample (P057), derived from the same patient but at an earlier time than sample P057-2, had a PI>2; p18 gene content was nearly two-fold decreased in P057, suggesting the possibility that most tumor cells have mono-allelic deletion of p18, perhaps with some tumor cells have bi-allelic deletion, and also some contamination by normal cells. The gene discussed is CDKN2C; the disease is neoplasm.