T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain （TIGIT） is a new immune checkpoint protein. Studies have shown that TIGIT can cause dysfunction of immune cells，weaken the anti-tumor effect，thus leading to tumor immune tolerance and immune escape. Blocking TIGIT can reverse immune cell failure and exert anti-tumor effect，which is expected to become a new therapeutic target for multiple myeloma.