Macropinocytosis is the major form of endocytosis responsible for the majority of fluid-phase uptake for a number of cell types [32] . Macropinocytosis is characterised by actin-dependent reorganisations of the plasma membrane to form macropinosomes, morphologically heterogenic vesicles that lack coat structures. Macropinocytosis is constitutive in many cell types but in others requires activation by growth factors [32, 33, 34] and contributes significantly to antigen presentation by specialised antigen presenting cells [32, 34, 35] . Macropinocytosis is also exploited by a wide range of important animal pathogens for cell invasion and possibly the avoidance of immune surveillance [36] .