A method for the in vitro evaluation of the toxic effects occurring in human cell lines upon the expression of genes from a range of pathogens is proposed. The method is based on the transient expression of the genes in the HEK293 cell line. Induction of cell death upon the expression of the gene coding for protease 3C from the human hepatitis A virus has been demonstrated for the first time using the method proposed. Expression of the gene coding for protease 2A from human poliovirus has also been shown to induce cell death, while cathepsins B and D did not have a cytotoxic effect on the culture used. © 2013 Pleiades Publishing, Inc.