Along this line, CNS infiltration by myeloid cells was demonstrated on biopsy samples from patients with MS, which was corroborated by the ability of triggering receptor expressed on myeloid cells 1 (TREM1)-targeted PET with 64Cu-TREM1-mAb to monitor deleterious innate immune responses and disease progression in the EAE mouse model of MS 192. The gene discussed is TREM1; the disease is myeloid sarcoma.