ESR1 and cancer: The genes they identified could be classified into two groups: i) genes implicated in preserving the integrity of the genome and genes commonly implicated in cancer (such as TP53, which is sometimes called the 'guardian of the genome', and TERT, which helps to ensure that the ends of chromosomes remain intact during cell divisions); ii) genes related to the development of the genitourinary system and genes involved in hormonal processes, some of which are also deregulated in cancers (such as the gene for the estrogen receptor gene ESR1).