[Gene therapy: facts and fiction].

The great advances in molecular biology have encouraged the treatment of diseases through gene intervention. According to present knowledge, all diseases somehow have their origin or are related to genes. Different stages must be overcome to intervene in genes: a) Identification of the gene to intervene. Methodologies have been developed and a number of genes identified. b) Codification of its structure. The technology for this purpose is already known and the process has been automated. c) Locate the adequate vector that, without damaging the cell, is capable to introduce in nucleus the genetic material. There are many studied alternatives. However the ideal vector, that would select the target cells, be risk-free and guarantee prolonged results, has not been found yet. d) To achieve the gene expression, codifying the respective protein or its inhibition, according to the case. Some success has been obtained in this field, but technology has to be improved to obtain a uniform and satisfactory response. Advances achieved in the last years have been impressive and technologies will presumably continue to improve.