This reciprocal lactate shuttle interplay between cancer cells and stromal CAFs was nicely demonstrated by Fiaschi et al. in prostate cancer (PCa) cell and fibroblast culture models, where contact of stromal fibroblasts with PCa cells and oxidative stress and hypoxia-inducible factor 1 subunit alpha (HIF1-α) stabilization within the fibroblasts were required for the Warburg effect’s production of lactate [8]. The gene discussed is HIF1A; the disease is prostate cancer.