In MS brain biopsy samples, CD4+CD28− T-cells were detected, which exhibited a cytotoxic phenotype and expressed CX3C chemokine receptor 1 (CX3CR1), a receptor that binds to the chemokine ligand 1 (CX3CL1) with the C-X3-C motif [55]. The gene discussed is CD28; the disease is myeloid sarcoma.