Fig. 1: Representative structure of TLS in AM.

A Representative H&E staining image of TLS (Indicated by the red arrow, Scale bars: 20×). B Representative mIF staining image of TLS (Markers: CD20, CD21, CD23. Scale bars: 100 μm). C Representative mIF sta ining image of TLS (Markers: CD4, CD8, CD68, CD10; Scale bars: 100 μm). D Representative mIF staining image of eTLS, pTLS, sTLS (left, middle, right column, respectively; Markers: CD20, CD21, CD23; Scale bars: 100 μm). TLS tertiary lymphoid structures, AM acral melanoma, mIF multiplex immunofluorescence, eTLS early tertiary lymphoid structure, pTLS primary follicle- like TLS, sTLS secondary follicle- like TLS.