Are GARD reproducing attractors catalytically closed? The degree of catalytic closure may be defined as a graded phenomenon, namely, the fraction of all molecular types in the network that receive catalytic influence. Nominally, catalytic closure is defined as a state when this fraction is equal to 1. It turns out that the capacity to reach the attractor has poor correlation with the degree of catalytic closure (Figure ). Further, different reproducing attractors show varying degree of catalytic closure, and only a small fraction (depending on the analyzed attractors at the high cutoff values) show a full catalytic closure. This, however is not unanticipated, as in modified versions of CAS networks some members of the network can be produced by uncatalyzed reactions with a nonzero rate , just as is built-in in the GARD model . One may thus conclude that catalytic closure is neither necessary, nor sufficient for attractor reproduction.