. 2021 Jul 21;13(15):3666. doi: 10.3390/cancers13153666
© 2021 by the author.
Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Figure 1.
Immune checkpoint molecules and their ligands.