  A kinetic system has an absolute concentration robustness (ACR) for a
molecular species if its concentration remains the same in every positive
steady state of the system. Just recently, a condition that sufficiently
guarantees the existence of an ACR in a rank-one mass-action kinetic system was
found. In this paper, it will be shown that this ACR criterion does not extend
in general to power-law kinetic systems. Moreover, we also discussed in this
paper a necessary condition for ACR in multistationary rank-one kinetic system
which can be used in ACR analysis. Finally, a concept of equilibria variation
for kinetic systems which are based on the number of the system's ACR species
will be introduced here.
