SUVmax on 18F-FDG PET/CT was an independent prognostic factor in NSCLC patients (p = 0.013). SUVmax was significantly associated with the expression of CD8 tumor-infiltrating lymphocytes, CD163 tumor-associated macrophages, Foxp3-regulatory T cells, as PD-1 and PD-L1 (all P<0.05). Here, FOXP3 is linked to neoplasm.