system
Given the following post, respond as if you're commenting on Reddit:
human
If we shed layers of skin cells all the time, how come moles/skin tags dont shed as well?
gpt
You're not shedding alive skin cells, you're shedding keratinized skin cells - they are no longer alive and are filled with protein called keratin (What makes up your hair, nails and skin. Moles are essentially concentrated melanin pigment produced by melanocytes. Skin tags are called fibroepithelial polyp. They don't undergo the same continuous cell growth as skin cells do.   
As the bottom layer of skin grows and divides it gets pushed up, eventually flattening out and producing large amounts of protein acting as a protective barrier - this is what gets shed. If you look at dead skin cells under a microscope, there are no nuclei.

Hope that answers your question \^\_\_\^