LAMP2 and melanoma: In a first set of experiments we confirmed data obtained in previous studies21,22, showing that Mel501 melanoma cells adapted to grow at pH 6.5 displayed different morphological features, as they appeared flattened and enlarged (Figure 1(A)), with a more intense staining for the lysosomal compartment marker Lamp-2, demonstrating the enlargement of intracellular vesicular compartment previously shown.29