PTGDR and systemic lupus erythematosus: For instance, DP1 expression was shown to be upregulated on circulating basophils from patients with systemic lupus erythematosus (Pellefigues et al., 2018), in microglia and astrocytes within senile plaques from individuals with Alzheimer’s (Mohri, 2007), and in cells of the crypt epithelium of patients with ulcerative colitis (Vong et al., 2010).