A method for predicting whether a patient diagnosed with a disease, disorder, condition or injury of the CNS is likely to be responsive or non-responsive to treatment with an immune checkpoint modulator is provided, wherein said method comprises determining ex vivo, in a blood sample obtained from the patient, or in a fraction thereof, a biomarker selected from: (a) the level of a monocyte subpopulation expressing CCR2, CD204 or a combination thereof, or CCR2 and a marker selected from igf1, lyve1, Stab-1, Siglec1 and Mrc1, or any combination thereof, (b) the ratio of the level of a monocyte subpopulation (CD14+ cells) expressing CCR2highCX3CR1low to a monocyte subpopulation expressing CCR2lowCX3CR1high; (c) the level of a CCR2 agonist; and (d) the level of a CCR2 antagonist.