What are the four main strategies of gene therapy for disease'What are the two main strategies of gene therapy for tumors?

Gene therapy is a method of treating diseases at the gene level. It includes gene replacement, gene correction, gene modification, gene inactivation, and introduction of new genes. The main 2 strategies: (1) gene correction: gene correction (gene correction) (gene correction): is the fixed-point introduction of exogenous positive fixed-point introduction of exogenous normal genes, instead of defective genes, on the target normal genes, instead of defective genes, on the target cell genome without any change. Belongs to the direct cell genome without any change. Belongs to the direct treatment. It is an indirect treatment.