Extracellular succinate implements an anti-inflammatory transcriptional response in M2 macrophages following a selective interaction with the G coupled receptor SUCNR1 [26], and SUCNR1 engagement by cancer cell-derived succinate initiates a PI3K/HIF-1α signaling pathway, skewing macrophages to a M2-like, pro-tumoral polarization [25]. This evidence concerns the gene HIF1A and cancer.