PCNA and neoplasm: The concomitant high expression of PCNA (a canonical marker of cell proliferation (19)), along with TYMS and DUT (key enzymes involved in deoxyribonucleotide synthesis and genomic fidelity (20, 21)), indicates that the STMN1+NK subset may represents a proliferative NK cell population poised for clonal expansion, potentially contributing to the maintenance and renewal of NK cells within the tumor microenvironment.