CYSLTR1 and glioblastoma: According to GEPIA [9] and Seifert et al. [8], expression levels of receptors for leukotrienes LTB4R1, LTB4R2, CysLTR1, CysLTR2, GPR17, and OXGR1/GPR99 do not differ between GBM tumors and healthy brain tissue.