Given the ubiquitous expression of the PAC1 receptor in the CNS [44] and retina [37], as well as recent finding pointing to a critical homeostatic role of the receptor in retinal function in a preclinical model of MS [41], we sought to determine the effect of ubiquitous PAC1 ablation on the gross brain architecture of the brain and retina using H&E staining. Here, ADCYAP1R1 is linked to myeloid sarcoma.