Expression trends of specific genes related to muco-ciliary function and airway restitution as compared with smoking status and lung cancer: TFF3, CABYR, and MUC5AC are over expressed in current smokers with lowered expression in both former and never smokers. Conversely, SCGB1A1 shows the opposite effect, with lowered expression in current smokers as compared to former and never smokers. MUC5AC and TFF3 are known to be components of mucus. EGFR levels are positively correlated with smoking status, with modestly higher levels in current smokers. MUC5AC and EGF have been shown to interact with EGFR in the process of airway restitution and SCGB1A1 has been shown to decrease levels of cyclooxygenase 2 (COX2) in cancer cells. Interestingly, within this process alone, we see reversible (TFF3, CABYR), partially reversible (MUC5AC) and completely irreversible (GSK3B) expression changes upon smoking cessation. Values refer to tag counts as tags-per-million (TPM).