CTSG and non-small cell lung carcinoma: Box plots were drawn based on the levels of CTSG expression in non-small cell lung cancer tissues and normal non-cancerous tissues (Fig. 2A), and the results demonstrated that the CTSG expression level in LUAD tissues (1.02) was significantly lower than that of normal non-cancerous tissues (6.57, log2FC =-1.906, P < 0.