the anatomy of the pump's pocket for carrying cargo (highlighted in blue) explains how this molecular machine is able to grab and eject a wide range of substances, including cancer drugs. credit: ella maru studiosometimes cells resist medication by spitting it back out. cancer cells, in particular, have a reputation for defiantly expelling the chemotherapy drugs meant to kill them. researchers at the rockefeller university have shed new light on a molecular pump that makes this possible, by determining its three-dimensional structure, down to the level of atoms. `this molecular machine ejects numerous anticancer agents, as well as other drugs. however, no one understood how it can recognize and remove such an impressive variety of substances,` says lead researcher jue chen, the william e. ford professor and head of the laboratory of membrane biology and biophysics.`by examining how this drug resistant pump binds to its cargo before transporting it, we have found an answer,` sh...