system
Given the following post, respond as if you're commenting on Reddit:
human
How do cells stick together?

We are formed of tissues that can be fairly strong! We can't for example take a handfull of our cells easily. How do they stick so well together?
gpt
Cells produce something called an extracellular matrix, which is a dense, complex network of very large proteins which stick to each other. The matrix surrounds the cells, and the cells produce proteins which attach them to the matrix. 

All cells do this, and in reality the body isn't just composed of cells holding on to each other - it's better to think of it as a large, resilient protein matrix which cells live inside. If you wanted to reach in and grab some cells, you have to also rip away the surrounding matrix, because they hold on so tightly with their adhesive proteins.