IDO1 and neoplasm: A Pickering emulsion loaded with tumor‐associated MUC1‐peptide antigens induced greater survival rate than other FDA approved adjuvants such as alum, MF59 and AS04.117 Another example of a microvaccine is a recombinant Saccharomyces cerevisiae (YCP) coated with an indoleamine 2,3‐dioxygenase (IDO) siRNA‐loaded nanoparticle and tyrosinase‐related protein 2 (Trp2).