Before revision:  In this situation, ordinary macroscopic-level fluctuations can be overwhelmed by non-negligible large fluctuations, which results in drastic changes in chemical-reaction dynamics and the resulting statistics compared to those observed under a large system size with a large number of molecules. Thus, analyses based on the average behavior of molecules valid at a macroscopic level (i.e., with a large-number limit) will not necessarily hold when considering a small size system containing a much smaller number of molecules  .
After revision:  In this situation, ordinary macroscopic-level fluctuations can be overwhelmed by non-negligible large fluctuations, which results in drastic changes in chemical-reaction dynamics and the resulting statistics compared to those observed under a macroscopic system (i.e., with a large-number limit) will not necessarily hold when considering a small size system containing a much smaller number of molecules .