Careful examination (GSE67806) showed that the expression levels of genes upstream (Atoh7, Pbld1, Pbld2, Nnrnph3, Dna2, Slc25a16, Tet1, Snord98, Ccar1, Stox1, Ddx50, Ddx21) or downstream (Vps26a, Supv3I1, Hk1, Tacr2, Tspan15, Neurog3, Col13a1) of serglycin did not differ significantly between SG+/- and SG-/- tumours, indicating that heterozygotes are appropriate as controls. The gene discussed is DDX21; the disease is neoplasm.