Observations of VPAC1-IR within the adjacent grey matter (GM) of selected MS cases (black arrowheads in Figure 7B′′–D′′) showed moderate cytoplasmic reactivity in neurons and no staining of GM oligodendrocytes, providing some degree of assurance regarding the specificity of the antibody used for VPAC1 detection. Here, VIPR1 is linked to myeloid sarcoma.