Although data remain limited in MFS, existing evidence suggests a heterogeneous immune landscape, including: i) variable expression of immune checkpoint molecules such as Programmed Cell Death Protein 1 (PD-1) and Programmed Death-Ligand 1 (PD-L1), ii) presence of tumor-infiltrating lymphocytes, iii) alterations in antigen presentation pathways, and iv) a pronounced angiogenic signature. Here, PDCD1 is linked to neoplasm.