GPR18 and neoplasm: The expression levels of the distinct genes of the RvD pathway ALOX15, ALOX15, FPR2, GPR18, GPR32, HPGD and PTGR1 were leveraged from 516 bulk tumor HNSC RNA-seq data, profiled by TCGA and plotted as a heatmap of individual tumor samples (Figure 2A).