Correlation of AR expression or nuclear localization with expression of the proliferation marker Ki-67. A. Representative images of two cells acquired with ImageStreamX that were multiplex stained for Ki-67, AR, and FxCycle Violet. Images represent cells with low AR expression, non-nuclear AR, and low Ki-67 staining (top panel) or high AR expression, nuclear AR, and high Ki-67 staining (bottom panel). B. Box-and-whisker plot showing the Ki-67 expression of AR-low (AR intensity <103), AR-intermediate (AR intensity 103 - 104), and AR-high (AR intensity >104) CTCs from all samples that had Ki-67 staining and cells in all three AR expression groups (n = 16 patients). C. Box-and-whisker plot showing the Ki-67 expression of CTCs with low similarity index (SI <0), intermediate similarity index (SI 0-1), or high similarity index (SI >1) from all samples that had Ki-67 staining and cells in all three similarity index groups (n = 10 patients) (* p-value <0.05, ** p-value <0.01, *** p-value <0.001).