Consistent with the increased expression of PSAT (Fig. 6a, b), MYC+N1ICD tumours had greater 13C incorporation into 13C1- and 13C2-serine (Fig. 6d and S10c), presumably produced by the Ser/Gly exchange reaction catalysed by SHMT (see Fig. S5c for full description) from 13C2-glycine than NC lung (Fig. 6d). The gene discussed is SHMT2; the disease is neoplasm.