ERBB2 and breast cancer: For breast cancer, a total of 44 therapeutic cancer vaccines are currently being investigated with ongoing clinical trials as of 23rd June 2021 (Corti et al., 2022), of which, 30 clinical trials are open to TNBC patients, 21 clinical trials are enrolling HER2-positive breast cancer patients while there are only 15 trials with hormone receptor-positive breast cancer as inclusion criteria.