CDKN2A and cancer: ADP-ribosylation factor-like tumor suppressor gene 1 is a member of the ARF family, the Ras superfamily of small guanosine triphosphatases known to be involved in numerous regulatory pathways in the multistage developmental process of human cancers.2 Structural and functional disorders caused by the ARLTS1 gene in cancer are of 3 types: genomic loss, gene polymorphisms, and epigenetic changes.