* DNA is the genetic material of cells. It's housed within the nucleus of every cell and contains the instructions for building and maintaining an organism.

* Glands are specialized tissues that produce and secrete substances. These substances can be hormones, enzymes, or other chemicals that have specific functions within the body.

* Secretion involves releasing a substance from a cell. This release is typically through a process called exocytosis.

DNA is not secreted because:

* It's not stored in glands. DNA resides within the nucleus of all cells, not just specialized gland cells.

* It's not designed for release. The primary function of DNA is to serve as the blueprint for an organism, not to be released as a secretion.

There are instances where DNA might be found outside of cells, but this is not due to secretion:

* Cell death: When cells die, their DNA is released into the surrounding environment.

* Certain biological processes: Some processes, like apoptosis (programmed cell death), involve the controlled breakdown of cells, including their DNA.

Therefore, while DNA is a vital part of our biology, it's not a substance secreted by glands.