This site's own mechanism sequence lists this specific fourth step — worth understanding it on its own, before the two broader steps that close the sequence.
This site describes it directly: Pantothenic Acid is positioned to reinforce the skin's natural moisture barrier from within — the single-ingredient step tied specifically to Pantothenic Acid in this site's own sequence.
Worth noting the two steps that follow this one — the inside-out approach and the gradual timeline — are broader, formula-wide framings, distinct from the four preceding, ingredient-specific steps.