As mentioned earlier, the lack of a significant reduction of the TSG101 protein in the original ‘TSG101-deficient’ SL6 cells should have raised questions about its assigned tumor-suppressive role as well as the validity of subsequent findings when these cells were used for mechanistic studies on the molecular functions of TSG101 without proper validation of the TSG101 protein expression using quantitative methods. This evidence concerns the gene TSG101 and neoplasm.