Although the PD data demonstrated durable blockade of soluble and membranous CD200R1 on immune cells from blood samples for participants dosed with 60 mg or more, this dose is unlikely to be sufficient to maximize pharmacology in tumor lesions; up to 10- to 20-fold higher doses of 23ME-00610 may be needed to saturate CD200R1 in the tumor microenvironment for the following reasons. Here, CD200R1 is linked to neoplasm.