Nef gene in HIV is for use:

Ans. is 'c' i.e., Decreasing viral replication(Ref: Ananthanarayan, 9th/e, and 8th/e, p. 571)Nef (Negative factor gene): Downregulating viral replication. QThe Nef protein increases viral infectivity, facilitates activation of resting T cells, and downregulates expression of CD4 and MHC class I. The Nef gene is necessary for simian immunodeficiency virus (SIV) to be pathogenic in monkeys. (Jawetz)