CD274 and cancer: The exploration of LNPs, which carry double‐stranded siRNA for the purpose of knocking down checkpoint inhibitors such as anti‐PD‐L1, indoleamine 2,3‐dioxygenase 1 (IDO), and transcription factor forkhead box P3 (FOXP3), among others, is being investigated for the treatment of cancer, as well as for in vitro engineered DC vaccines.111