This app is designed to provide a handy reference in diagnostic immunohistochemistry during daily sign-out for both practicing pathologists and trainees. IHC stains are used routinely in daily practice, but the extensive IHC literature in textbooks and online resources can be hard to access and navigate. This easy to use app allows for selection of appropriate IHC stain panels in an algorithmic work-up of tumors. This release provides the most up-to-date information on individual tumor IHC profiles and antibodies. Clinically relevant molecular pathology information is also included for some tumors.