Targeted therapy is a type of medication that blocks the growth of cancer cells by interfering with specific targeted molecules required (i.e. specific markers which are present as cancer cells). That is why, they kill only the bad cells i.e. cancer cells and spare the Normal or food cells. Cancer researchers have discovered some of the differences within cancer cells that enable them to thrive. Targeted therapy refers to treatment with drugs that have been developed to “target” these differences within the cell. Unlike chemotherapy, targeted therapy drugs alter the inner workings of the cell focusing on the part of the cancer cell that makes it different from the normal, healthy cell. Because they leave the healthy cells alone the side effects of targeted therapies are different from standard chemotherapy treatments.