I would like to propose the recent papers by Janmey, P.A., and coworkers on the nonlinear elasticity behavior of biopolymer gels for "biomechanics" issue in J Club. In their original work, they proposed the biopolymer network model composed of semi-flexible polymers that behave like a worm-like-chain (WLC) model. Their models surprisingly capture the mechanical response of biopolymer gels such as neuro-filaments. The details of their work are as follows: