Five different gating patterns are illustrated on the top of the table. The number of events and percentage for each pattern are displayed. The corresponding CFTR mutants and ATP concentrations are shown on the left. #, the (O1–O2)_n category includes events that contain at least one O2→O1 transition (such as C→O1→O2→O1→O2→C, C→O2→O1→O2→C, C→O1→O2→O1→C, C→O1→O2→O1→O2→O1→O2→C, etc.). Thus, this category in theory can be dissected into more subfamilies, but the majority of the events sorted into the (O1–O2)_n category assumes a pattern of C→O1→O2→O1→O2→C, i.e., reentry occurring only one time in a burst. Because the frequency for such events is already low (∼10%), the frequency becomes even lower for opening bursts with more than one reentry event. The probabilistic nature of the distribution of these gating patterns dictates that the number of gating patterns depends on the number of event (or the duration of recordings) collected. Therefore, for simplicity, we lumped all events with more than one reentry into a single category.