While LC3‐II and SQSTM1/p62 levels in peripheral blood have been used as proxies for autophagy in tumor cells, their utility is not without limitations.[391] For example, in patients with early‐stage solid tumors treated with HCQ, the secretion of Par‐4 correlated with apoptosis in the cancer but did not correlate with the autophagy inhibition marker p62 (NCT03015324), highlighting the need for more precise and tumor‐specific biomarkers to evaluate autophagic activity and its therapeutic implications effectively.[391]. Here, SQSTM1 is linked to cancer.