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Strain stiffening induced by molecular motors in active crosslinked biopolymer networks magnitudewhen subject to large stresses. Cells also employmolecular 1 network by about two orders of magnitude. The degree of stiffening was found that in distinct contrast to FLNa, scruin does not promote active stiffening of F-actin networks upon addition of myosin. These results clearly show that actomyosin contractility when combined with appropriate crosslinks can allow the cell to operate in a nonlinear regime to actively control its mechanical response. Why do compliant crosslinks in active networks lead to large strain stiffening while no significant increase in stiffness is observed in the case of incompliant crosslinks? To answer this question and to quantitatively study the interplay of internal strains generated by molecular motors and external loads, we study the mechanical response of active networks using finite element simulations where the motors are treated as force dipoles (Fig. 1). A number of COMMUNICATION www.rsc.org/softmatter | Soft Matter D ow nl oa de d by B r