  Generalized transverse-momentum dependent parton distributions (GTMDs) encode
the most general parton structure of hadrons. Here we focus on two twist-2
GTMDs which are denoted by $F_{1,4}$ and $G_{1,1}$ in parts of the literature.
As already shown previously, both GTMDs have a close relation to orbital
angular momentum of partons inside a hadron. However, recently even the mere
existence of $F_{1,4}$ and $G_{1,1}$ has been doubted. We explain why this
claim does not hold. We support our model-independent considerations by
calculating the two GTMDs in the scalar diquark model and in the quark-target
model, where we also explicitly check the relation to orbital angular momentum.
In addition, we compute $F_{1,4}$ and $G_{1,1}$ at large transverse momentum in
perturbative Quantum Chromodynamics and show that they are nonzero.
