Diffusion coefficients and confinement areas of HaloTag-tagged proteins that are associated or unassociated with RNAP2 Ser2ph-enriched regions. (A and B) D values and confinement areas of HaloTag-tagged proteins that are associated or unassociated with RNAP2 Ser2ph-enriched regions (A) and the area of confinement (B) of bound HaloTag-tagged proteins compared between the molecules that were highly associated (magenta, top 25% I_{rel_Ser2ph}) and lowly associated (green, bottom 25% I_{rel_Ser2ph}) with RNAP2 Ser2ph-enriched regions, with P values derived by Mann-Whitney U test and the numbers of analyzed bound molecules (n). Box plots from two independent replicate experiments are shown. Center lines show the medians; box limits indicate the 25th and 75th percentiles; whiskers extend 1.5 times the interquartile range from the 25th and 75th percentiles; outliers are represented by gray dots. The corresponding scatterplots with the median D values and effective spring coefficients are shown in Fig. S4.