Hsd17b7, also known as 17β-hydroxysteroid dehydrogenase type 7 or prolactin receptor-associated protein, is an enzyme-encoding gene. It has a dual function in sex steroid and cholesterol biosynthesis [1,3,4,6]. In sex steroid synthesis, it converts estrone to estradiol, and in cholesterol biosynthesis, it acts as the 3-ketoreductase in the postsqualene cholesterol biosynthesis pathway [3,5]. This gene is of great biological importance as it is involved in multiple physiological processes, and genetic models can be used to further explore its functions.

In a knockout mouse model, deletion of exons 1-4 of the Hsd17b7 gene led to no viable null mice. Hsd17b7 null embryos were alive on d 8.5 and d 9.5 but by d 10.5, they suffered from severe brain malformation and heart defect, likely due to the role of this enzyme in cholesterol synthesis required for brain development [6]. Also, genetic suppression of Hsd17B7 increased the formation of oligodendrocytes, suggesting its role in neurodegenerative-related contexts [2].

In conclusion, Hsd17b7 is crucial for embryonic development and fetal survival due to its role in cholesterol biosynthesis [6]. Its function in promoting oligodendrocyte formation indicates its potential significance in neurodegenerative diseases [2]. Studies using knockout mouse models have provided valuable insights into the essential biological functions of Hsd17b7 and its implications in specific disease areas.