DES, or Diethylstilbestrol, is a transplacental endocrine-disrupting chemical, not a gene. It was a synthetic non-steroidal oestrogen prescribed to pregnant women from the 1940s to prevent miscarriages and other pregnancy disorders, despite lacking proven efficacy [1,2,3,4]. It is classified as carcinogenic to humans and has far-reaching impacts on human health [1].

DES has caused extensive deleterious effects. Pregnant women who took DES, as well as their children and grandchildren, have been affected. It is associated with an increased risk of cancers (such as breast cancer, clear cell adenocarcinoma of the vagina and cervix), abnormalities of the genital tract, neurodevelopmental alterations, problems related to socio-sexual behavior, and immune, pancreatic, and cardiovascular disorders [1]. Epidemiological studies show that in utero exposure to DES can lead to higher risks of preterm delivery, neonatal mortality, stillbirth, malformations, hypospadias in grandsons, and oesophageal atresia or tracheo-oesophageal fistula in grandchildren [2].

In conclusion, DES is a harmful endocrine-disrupting chemical that has had long-lasting and multi-generational effects on human health. The study of its impacts, though not from gene knockout models as it's not a gene, helps us understand the long-term consequences of exposure to such chemicals during pregnancy and the importance of careful drug prescription in the future [1,2,3,4].