To validate this discrepancy, the RT‐qPCR showed that the relative mRNA expression levels of CTSH were significantly lower in the lung adenocarcinoma specimens and cell lines (A549 and H1975) compared to the normal ones (Figure 6M), whereas the Western blotting revealed the higher expression of CTSH in tumor specimens at the protein level (Figure 6N). Here, CTSH is linked to lung adenocarcinoma.