Control histograms of φ distributions. (A) The histograms of Rtn4 (green), Sec61β (magenta), and KDEL (yellow) together. The distributions were tested for significant differences using a rank sum test (Rtn4 vs. Sec61β: P <<< 0.001; Rtn4 vs. KDEL: P <<< 0.001; Sec61β vs. KDEL: P <<< 0.001). (B) Polar histogram of φ from analysis using the nanobody localizations of Sec61β. There were 765,458 unique angle calculations total across the n = 3 biological replicates, respectively. (C) Polar histogram of φ from analysis using the nanobody localizations of KDEL. There were 889,347 unique angle calculations total across the n = 3 biological replicates, respectively. (A–C)n = 3 cells from unique sample preparations; error bars represent the standard deviation of the frequency of each histogram bin between biological replicates.