Markov chain of the transition probabilities between state cycles in the cholesterol regulatory pathway. Let k be the number of states within an attractor (k can be 1 in the case of a point attractor) and N be the number of species in the model. For each attractor of this finite time-homogeneous Markov chain, we perturb each species of each state by triggering its own Boolean function asynchronously. Thus there are kN perturbations per attractor. In the cholesterol regulatory pathway, one cyclic attractor found by the synchronous analysis has 29 states and the three other cyclic attractors have 33 states. The number of species in the model is 33. The weight of the edge from an attractor X to an attractor Y is the ratio between the number of perturbations of X which lead to Y over the total number of perturbations of X.