Un bien fundamentado y prestigioso análisis realizado en 1989 por el Consejo Nacional de Investigación de EEUU resumió el consenso científico: "Con las técnicas clásicas de transferencia genética, es posible transferir una cantidad variable de genes, dependiendo del mecanismo de transferencia.
An authoritative 1989 analysis of genetic technologies by the US National Research Council summarized the scientific consensus: "With classical techniques of gene transfer, a variable number of genes can be transferred, the number depending on the mechanism of transfer; but predicting the precise number or the traits that have been transferred is difficult, and we cannot always predict the [traits] that will result.