This book presents the functions and mechanisms of macropinocytosis, an actin-driven endocytic uptake process. Key points, including the evolutionary origins of macropinocytosis and major signaling pathways that regulate this uptake mechanism, are highlighted. A wide-array of functions of macropinocytosis are described, including cellular metabolism, cell death, cell migration and antigen presentation. Macropinocytosis has recently been recognized...