Typically, when the inversion channel has formed in a nMOSFET and the drain voltage is swept, the channel current is positive, meaning a sourceto- drain electron flow. This can be observed in transistors with channel lengths not longer than 80 nm. A set of experimental results showing a reversible channel current effect in a 34 nm nMOSFET is introduced. This effect means that the electrons suffer a change in the direction, now flowing from drain-to-source. By numerical modeling it was found that the reversible channel current effect is understood by incorporating the Density Gradient (DG) theory, which is considered an enhanced drift-diffusion model. The enhancement comes from considering quantum nature effects that are negligible when working on the micrometer scale (transistors with channel lengths longer than 80 nm). The phenomenon is explained by a change of sign in the gradient of the generalized quantum potential along the channel. The effect is only observable at low drain voltages, where a slight initial internal channel conductance (at no bias) unbalance causes the channel current to reverse when the gate voltage sweeps from low to high values.