Immunoblotting was carried out as previously described (15 (link)) with diluted (1:1000) anti-PHGDH antibodies (HPA021241; Sigma), anti-HIF2α antibodies (ab51608; Abcam, Cambridge, MA, USA), anti-glyceraldehyde 3-phosphate dehydrogenase antibodies (GAPDH; MAB374, EMD Millipore, Billerica, MA), and anti-β-actin antibodies (bs-0061R; Bioss, Woburn, MA, USA). Immunohistochemistry were performed using an UltraVision Detection System (Thermo Scientific, Fremont, CA, USA) according to the manufacturer’s instructions. The primary rabbit monoclonal antibodies against Ki67 (ab92742; Abcam) were diluted 1:100. For immunofluorescence analyses, nuclei were stained with DAPI (1 μg/mL; Kirkegaard & Perry Laboratories, Gaithersburg, MD, USA), and slides were mounted in Fluoromount (Diagnostic Biosystems, Pleasanton, CA, USA). Anti-PHGDH antibodies (HPA021241; Sigma) were used as the primary antibody at a dilution of 1:100, and binding was visualised using secondary antibodies conjugated to Alexa Fluor 488 (ab150077; Abcam).