Synonymous codon pair deoptimization is an efficient strategy for virus attenuation; however. the underlying mechanism remains controversial. Here. we optimized and deoptimized the codon pair bias (CPB) of the human immunodeficiency virus type 1 (HIV-1) envelope (env) gene to investigate the influence of env synonymous CPB recoding on virus replication capacity. https://ashleyshomestores.shop/product-category/compact-fridge/