All panels in this figure used 20 µM (unless otherwise indicated in a) mEGFP-UTX (419-848) WT or mutants as indicated. S781Y and S814F mutation was found in one and two patients, respectively, and both were predicted by ICGC to have high functional impact. 5M is a compound missense mutation containing S674Y, S781Y, H808Y, S814F, and S818L, all found in one cancer patient. See Methods “Cancer database analysis for mutations” for details. a. Pictures and relative turbidity as OD600 normalized to the value of WT and plotted as mean ± SD. n = 3 independent experiments. Bottom, coomassie blue staining of the corresponding proteins, sometimes with finely adjusted (10%) different concentrations (for S814F) to ensure fair comparison with WT. b. Representative fluorescence microscopy and DIC images at indicated times in condensation. Scale bar, 10 µm. c. FRAP recovery curves as mean ± SD at indicated early and late times in condensation. Top two panels, n = 13 droplets for WT and S781Y each at early times, and n = 9 for each of them at late times. Bottom two panels, n = 9, 10, 10 for WT, 5M, S814F, respectively, at early times, and n = 8 for each of them at late times. The statistics is for the last time points, but, for WT and S814F at late condensation times, is for 0-143 seconds after photobleaching. d–f. Line RICS assays for WT (n = 21 droplets), S781Y (n = 12), S814F (n = 10), and 5M (n = 11) over the time range of 0-100 min in condensation. d. Fluorescence Images and line carpets. e. Line RICS autocorrelation curves. f. Plot showing the mean ± SD of the diffusion coefficients. ***P<0.001, and ****P<0.0001 by two-sided t-test for all.