ERK inhibitor is used in cancer research and drug development, particularly for targeting tumors with mutations in the RAS/RAF/MEK/ERK signaling pathway. This pathway is often overactive in cancers such as melanoma, lung, and pancreatic cancer. By inhibiting ERK, these compounds help block abnormal cell growth and promote cancer cell death. They are especially valuable in cases where tumors develop resistance to earlier pathway inhibitors like BRAF or MEK inhibitors. ERK inhibitors are being tested in clinical trials to evaluate their effectiveness alone or in combination with other therapies. Their role in restoring sensitivity to treatment makes them a promising tool in precision oncology.