EGFR inhibitors are a class of targeted cancer therapies that block the activity of the epidermal growth factor receptor (EGFR), a protein that helps cells grow and divide. By inhibiting this receptor, these drugs can slow down or stop the growth of certain types of cancer, particularly non-small cell lung cancer and colorectal cancer. These medications can be administered orally or intravenously and are often used in patients whose tumors have specific mutations in the EGFR gene. Common examples of EGFR inhibitors include erlotinib, gefitinib, and afatinib. While they can be effective, they may also cause side effects such as skin rashes and gastrointestinal issues.