2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/46627It is shown that the latest results from NMC and E665 on the $F_2^A(x)/F_2^{D}(x)$ obtained in the shadowing region, bring new evidence of the universal $A$ -- dependence of distorsions of a free nucleon structure function by nuclear medium. The universality holds in the entire $x$ -range and can be explained as a saturation of the distortions of the parton distributions in a four-nucleon system.7 pages (LaTeX) and 13 Postscript figures, transformed to 4 figures in the body of the paper. Contributed paper "pa06-016" to the ICHEP'96, WarsawHigh Energy Physics - PhenomenologyNuclear Theorytext