TIGIT and glioblastoma: —Vincze et al. developed a novel immuno-PET tracer, [89Zr]-DFO-anti-TIGIT (89Zr-αTIGIT), to visualize TIGIT (T-cell immunoreceptor with Ig and ITIM domains) expression within the tumor microenvironment of glioblastoma.57 TIGIT is an immune checkpoint receptor present on activated T-cells and natural killer (NK) cells that suppresses immune responses by binding to ligands like CD155, inhibiting T-cell and NK-cell functions.