On this point, the synergisms observed between HH inhibition and checkpoint blockade in some cancer types may reflect a hierarchy of immune-suppressive events, where the activation of HH signaling decreases the initial immune response by reducing the ability of T cells to infiltrate the tumor, whereas PD1/PDL1 signaling is engaged at later stages by repressing T cell effector functions. Here, PDCD1 is linked to neoplasm.