“…Various clustering algorithms have been developed to quantify the degree or variability of clustering of a protein of interest under various conditions. Examples include local clustering algorithms that define boundaries of dense localizations ( Ester et al, 1996 ; Perry, 2004 ; Owen et al, 2010 ; Pageon et al, 2016a ; Griffié et al, 2016 ; Levet et al, 2019 ; Khater et al, 2020 ; Nino et al, 2020 ; Simoncelli et al, 2020 ; Williamson et al, 2020 ; Marenda et al, 2021 ; Nieves et al, 2021 ) or bulk metrics based on the radial distribution or pair-correlation function that quantify the density of localization pairs as a function of their distance to each other ( Ripley, 1979 ; Kiskowski et al, 2009 ; Sengupta et al, 2011 ; Veatch et al, 2012 ; Stone and Veatch, 2015 ). Importantly, these analysis methods can be expanded to two-color SMLM data to quantify the colocalization and structural relation of two proteins.…”