From the abstract of the paper, significantly more nuance.
> Despite persistent immune aging phenotypes, GzmK deficiency markedly attenuated organ aging, effectively uncoupling immune and tissue aging... These findings identify GzmK as a tissue-specific driver of organismal aging but not immune aging or systemic inflammaging.
Paywall
Paper: https://www.cell.com/immunity/fulltext/S1074-7613(26)00440-1
Granzyme K is the protein.