Other smoking-induced changes among the highly expressed SAE-enriched genes included up-regulation of oxidative stress-related genes ALDH3A1 and GSTA2, also associated with cancer development [116,117], and down-regulation of genes associated with epithelial differentiation such as CD74, C9orf24 (also known as ciliated bronchial epithelium 1), and luminal cell-associated keratin 19[118,119]. Here, SPMIP6 is linked to cancer.