Fig. 2
From: Impact of tissue sampling on accuracy of Ki67 immunohistochemistry evaluation in breast cancer
Linear regression results for single random selection. Linear regression analysis results for hexagon size = 825 pixels ≈ 0.75 mm TMA core. Ratios by sum, median and mean were used on a subset of hexagons. Results are divided by tumor heterogeneity. Note that y-axis begins at R2 = 0.6 for better visualization of differences between groups of measurements