VIPR2 and myeloid sarcoma: Upon examining the gene expression levels of the PAC1 (ADCYAP1R1), VPAC1 (VIPR1) and VPAC2 (VIPR2) receptor genes in the NAWM of all MS patients combined, no statistically significant differences were observed (p = 0.357, p = 0.2987 and p = 0.6558, respectively; Figure 3A–C).