CTLA4 and neoplasm: We found that for mice with their primary tumours eliminated by PLGA-ICG-R837-based PTT in combination with CTLA-4 blockade, their secondary tumours showed almost completely inhibited growth for the 4T1 model, and disappeared for the C26T model, achieving efficacies much better than that obtained in the surgery groups receiving the combined PLGA-ICG-R837 plus anti-CTLA4 treatment.