Blocking CD200R1 does not affect macrophage responses to Aldara cream or Imiquimod. (A−B) Aldara cream‐induced psoriasis‐like skin inflammation with CD200R1 blockade or isotype control. (A) Skin macrophage numbers and costimulatory molecule expression. (B) Proportion of skin macrophages producing cytokines, measured by flow cytometry. (C−D) Imiquimod stimulated BMDM with CD200R1 blockade, or isotype control. Cytokine production by flow cytometry (C), and ELISA, (D). Each data point is from a separate (individual mouse) BMDM culture. Data pooled from 2 to 3 independent experiments (n = 4−11). Mean and SD shown. Analyzed using unpaired t‐tests (for two groups of data, [D]) or Brown−Forsythe and Welch analysis of variance (for >2 groups of data, A−C) with Dunnett's test. *p < .05, **p < .01, ***p < .001. BMDM, bone marrow‐derived macrophages.