A segment of DNA that is involved in producing a polypeptide chain; it can include regions preceding and following the coding DNA as well as introns between the exons; it is considered a unit of heredity. The above definition of a gene though baffling makes us understand the simple fact that genes are proteins that are an integral component of every chromosome in each cell of the body, says Surgical Gastroenterologist Dr. S. Srivatsan.

https://www.drsrivatsan.com/explaining-the-genetics-of-cancer/