I MDA‐MB‐231 cells stably expressing Flag‐LAPTM4B were stained with LAPTM4B anti‐sera followed by silver‐enhanced immuno‐electron microscopy. The early and late MVEs were defined by the number of intraluminal vesicles. N, nucleus; M, mitochondria; MVE, multi‐vesicular endosome; and PM, plasma membrane. Scale bars: 2 μm (left); 200 nm (middle and right). 