However, therapies with an antibody targeting PD1 (anti‐PD1) displayed response rates from 17% to 21%, with some responses being remarkably durable.13, 14 The reason for this phenomenon may be tumor mutational burden15 or cytokine release syndrome.16 However immune responses and diseases are not caused by a single immune cell or checkpoint, their interaction relationship changes.17 Therefore, studies of the relationship between the tumor and host microenvironment have revealed that interactions between the immune microenvironment and molecules affect the therapeutic outcome of patients. Here, PDCD1 is linked to Down syndrome.