Proton mass decomposition: Naturalness and interpretations

I discuss the scope and naturalness of proton mass decomposition (or sum rule) published in Phys. Rev. Lett. 74, 1071 (1995) answer a few criticisms that appeared recently literature, focusing particularly on its interpretation quantum anomalous energy contribution. comment so-called frame-independent or invariant-mass from trace energy-momentum tensor. stress importance measuring through experiments. Finally, point out large discrepancy scalar radius nucleon extracted vector-meson productions lattice QCD calculations.