In this case, to take advantage for future study design, an adjuvant with cross-presentation enhancing function, e.g., Toll-like receptor 4 agonists that have been licensed clinically as vaccines adjuvants for human papillomavirus and melanoma for its enhancement on processes associated with cross-presentation, can be co-administrated with either E75 or GP2 vaccine to aid the loading of exogenous antigens to MHC I class molecule and CD8+ T lymphocyte activation (Ho et al. 2018; Lee and Suresh 2022). Here, TLR4 is linked to melanoma.