MDA‐MB‐231 cells expressing GFP‐Rab5Q79L were starved and stimulated with 100 ng/ml Alexa‐555‐EGF for 90 min followed by fixation and immunostaining for LAPTM4B (blue). The percentages of luminal Alexa‐555‐EGF in individual endosomes were plotted against endosomal LAPTM4B levels. Trend lines and Pearson's correlation coefficients are shown. Data are representative for three independent experiments. 