In the theory it is predicted that the drag current is Coulomb gapped. This is partially seen in the experiment. Considering the dot level \(-\epsilon_2=0.12 meV\) in a region where the dot charge in dot 2 changes from \(M\rightarrow M+1\), then the drive current \(G_1\) versus \(-\epsilon_1\) and \(V_{S1}\) shows a region where transport is favored. Now we look at the drag current that looks to be correlated with \(G_1\) but it does not show any Coulomb gap. However, if we look at the case where \(-\epsilon_2=0.47 meV\) in which the stability digram for the two dots shows no transport at all, then we observe that the drag current (even if it is very noisy) has a Coulomb gap region.