When several pools of the same lipid exist within the cell, low or high affinity sensors will behave differently with respect to these pools. A) A low affinity sensor (e.g., 1xLBD) will localize to both membranes with slightly more sensor molecules at the compartment with the highest lipid concentration, while (B) a high affinity sensor (e.g., 2xLBD) will localize preferentially to the compartment with the highest lipid concentration. C) Example of low (1xPHFAPP1) and high (2xPHFAPP1) affinity sensor localization in Arabidopsis root cell (image from Simon et al., 2014 Plant Journal).