Moreover, a recent study showed that OG probiotic Lr translocated from the gut and persistently colonised the tumours in melanoma mice, promoting the response of CD8 + T cells in TME and enhancing the therapeutic effect of anti-PD-L1.221 Thus, these microbial interventions may function through the gut-tumour microbiome crosstalk or a suitable niche provided by the TME, and direct intratumoural targeting may further enhance immunotherapy efficacy in the future. The gene discussed is CD274; the disease is melanoma.