Two nodes fighting for a win : bistability and stability loss in dynamics on GRN-like networks

One of the problems at the heart of osteoarthritis is chondrocyte hypertrophy. A study modelling the dynamics of chondrocyte hypertrophy showed three stable states: a SOX9-positive state linked to stable chondrocytes, a RUNX2-positive state linked to hypertrophy and a null-state linked to apoptosis. The question arose why the system is bi/multistable and why the RUNX2-state is reached. Through analysis of small networks similar to the large network used in the previously mentioned study, it was found that mutual inhibition seems to lie at the heart of bi/multistability.