We review the impact of potentially large higher-order corrections on trilinear Higgs couplings (THCs) and on the comparison between the experimental results and the theoretical predictions for the pair production of the 125 GeV Higgs boson at the LHC. We use the theoretical framework of the Two Higgs Doublet Model (2HDM), containing besides the SM-like CP-even Higgs boson h a second CP-even Higgs boson H, which we assume to be heavier, MH > Mh. Concerning the invariant mass distribution of the two produced Higgs bosons we demonstrate that the loop corrections to the THCs λhhh and λhhH as well as interference contributions give rise to important effects both for the differential and the total cross section. We discuss the implications for the experimental limits that can be obtained in the 2HDM.