The UK National External Quality Assessment Scheme (UK NEQAS) for immunocytochemistry and in situ hybridisation (ICC & ISH) is an international External Quality Assurance (EQA) provider. UK NEQAS ICC & ISH welcomes participation from both UK and non-UK based laboratories, offering EQA assessments in a variety of immunocytochemistry and ISH modules at approximately 3-monthly intervals throughout the fiscal year: Immunocytochemistry Modules: • General Pathology • Breast Pathology (ER, PR, HER2) • Gastric HER2 • Lymphoid Pathology • Alimentary Tract Pathology (GIST) • Mismatch Repair (MMR) Proteins • Neuropathology • Cytopathology • ALK IHC in NSCLC • ROS1 IHC in NSCLC (Pilot) • PD-L1 in NSCLC (Pilot) ISH Modules: • Breast HER2 ISH • ALK FISH in NSCLC (pilot) • ROS1 FISH in NSCLC (Pilot) In addition to EQA, UK NEQAS ICC & ISH provides education through feedback and technical advice. We provide useful information on methods and reagents to facilitate continual quality improvement of immunocytochemistry and in situ hybridisation. Furthermore, UK NEQAS ICC & ISH organise participant meetings, and engage in novel research and publications.