eLife Assessment
Rennert et al. developed a valuable thermodynamic framework to study the force response of branched actin networks from the crucial and unexplored perspective of energetic cost. They used the fact that the entropy production rate must be positive to derive inequalities that set limits on the maximum force produced by branched actin networks, and speculate that the dissipative cost beyond that required to move the load may be necessary to maintain an adaptive steady state. This work is highly innovative, but remains incomplete until the hypotheses of the model are better justified and the conclusions about the dissipative cost of the system are better established.