APOA2 and neoplasm: IFIT1+, SPP1+ and CCL4+ TANs were found to be pro-tumor, linked to a worse prognosis and expressing a high level of PD-L1; CD74+ TANs were associated with a better prognosis, but their relatively high PD-L1 expression raises doubts about their role in tumor progression; MMP8+ and APOA2+ TANs exhibited lower PD-L1 levels, correlating with a better prognosis and suggesting a potential anti-tumor role in HCC [36].