Differentially expressed gene analyses using The Cancer Genome Atlas (TCGA) database with the GEPIA2 online tool illustrate that CtsB is significantly upregulated in a variety of types of cancer, with its overexpression leading to a worse prognosis and reduced survival in a variety of human solid tumours, as previously reported [228,229,230,231,232,233,234,235] (Figure 3). Here, CTSB is linked to cancer.