Correspondingly, we observe aberrantly high expression of DARPP-32 proteins in SCLC patient-derived tumour specimens and undetectable levels in normal lung, a finding supported by our genomic analysis of a matched SCLC tumour and adjacent normal tissue RNA-Seq dataset.37 Genetic ablation of DARPP-32 isoforms in orthotopic SCLC xenografts decreases tumour growth, whereas overexpression of DARPP-32 or t-DARPP in human DMS-53 or H1048 SCLC cells orthotopically injected into mice increases SCLC growth. This evidence concerns the gene PPP1R1B and neoplasm.