A method is provided for treating a recipient with a biological product obtained from at least one donor that may be the same as, or different from, the recipient. The method includes identifying a targeted level of gene expression of a first gene in a biological product to be transferred from at least one donor to a recipient; treating the at least one donor to achieve the targeted level of gene expression of the first gene in the biological product; and transferring the biological product from the at least one donor to the recipient.