Visualization of heterogeneity of CXCR2⁺ TAN infiltration in MM BM and FLs. Vectra Polaris staining was applied to formalin-fixed, paraffin-embedded sections from 12 patient samples (BM, n = 12; paired FL, n = 12). Representative Vectra images from 3 individual patient samples ([A-C, top rows] original magnification ×10; [A-C, bottom rows] original magnification ×30). Differential marker and cell distribution of CD138⁺ tumor cells and CD16⁺ cells. (A) The absence of CXCR2⁺ cells in BM with <1% malignant PCs (CD138⁺). (B) Accumulation of CXCR2⁺ neutrophils along with an increase of CD138⁺ cells in BM. (C) Extensive intratumoral infiltration of CXCR2⁺ neutrophils with increased CD138⁺ cells. (D-F) Representative visualizations of the 3 mature TAN populations: (1) CXCR2⁺CD10⁺TNFAIP3⁺ cells (D, arrow), (2) CXCR2⁺CD10⁺TNFAIP3^– cells (E, arrow), and (3) CXCR2⁺CD10^–TNFAIP3^– cells (F, arrow). These data highlight the TAN heterogeneity and diversity within neutrophil populations in MM, emphasizing distinct phenotypic and functional subsets that may contribute variably to the TME.