PDCD1 and colorectal carcinoma: Lactobacillus rhamnosus GG oral administration to murine models was connected to an augmentation of immunotherapy anti-programmed cell death 1 (PD-1) antitumor activity, by T-cell and tumor-infiltrating DC increase [88], supporting the potential use of Lactobacillus rhamnosus GG in human CRC patients to raise their antitumor response and immunotherapy efficacy [89].