The AACR, or the American Association for Cancer Research, is a professional organization dedicated to advancing cancer research and its application to cancer treatment. Founded in 1907, it brings together scientists, clinicians, and other professionals to share knowledge and collaborate on innovative cancer research initiatives. The AACR hosts annual meetings, publishes scientific journals, and provides resources for researchers and healthcare professionals. Its mission is to promote the understanding of cancer biology, improve prevention and treatment strategies, and ultimately reduce the burden of cancer on society.