They may be synthesized and administered exogenously. One way is using exogenously regulatable promoter system in AAV vectors. Like 1,4-BD, it also behaves as a prodrug to GHB when taken exogenously. This indicates that exogenously caused DNA damages are likely repaired by crossover recombination in SCs. Therefore, when TRH is given exogenously, TSH levels increase. The cellular responses to exogenously applied GABA remained the same. Ultimately, a greater proportion of the exogenously provided levodopa/L-DOPA reaches the brain. Price and market condition is assumed to be given exogenously at equilibrium. And the neoclassical formulation assumes that the factors of production are given only exogenously. OSeMOSYS is driven by exogenously defined energy services demands. It arises exogenously from outer layer of cortex of the stem. Most models in traditional contract theory assume that asymmetric information is exogenously given. One set of these is the exogenously gives vector of export levels.