It has been suggested that 5–10% or more of the ≈25 000 putative genes encoded in the human genome probably contribute to oncogenesis.[4] However, only a small proportion of them have been experimentally confirmed to causally implicated in cancers.[5] C21orf58, expressed by chromosome 21 open reading frame 58 and located in 21q22.3, is a functionally uncharacterized gene.[6] The main isoform consists of 216 amino acids, and is mainly located in the cytoplasm, mitochondria, and nucleus of the cell. The gene discussed is C21orf58; the disease is cancer.