PHGDH and cancer: These results are in contrast to the data of the inhibitor’s developers, who observed only growth inhibitory effects of CBR-5884 in cancer cell lines with high PHGDH expression levels and a high propensity for serine synthesis.30 However, in this publication only concentrations up to 30 μM CBR-5884 were applied for cell proliferation assays, which is below the IC50 of 33 (±12) μM.30