LGALS9 and neoplasm: Key tumour–non-cancerous cell interactions include the PD-L1/PD-1 (CD274/PDCD1) [84] and Galectin-9/TIM-3 (LGALS9/HAVCR2) [85] pathways, which are significantly upregulated in Low TPS and show a negative correlation with TPS, indicating the influence of the tumour microenvironment (TME).