From residue to cancer risk: How thirdhand smoke drives cancer hallmarks

Figure 1 Thirdhand smoke chemicals and the hallmarks of cancer. This schematic illustrates the relationships between major thirdhand smoke (THS) constituents and key cancer hallmarks. Left panel: Sources and categories of THS exposure. Middle panel: Principal chemical components of THS and their transformation processes in indoor environments. Right panel: Mechanistic links between THS constituents and hallmark processes, including sustaining proliferative signaling, resisting cell death, genome instability and mutation, tumor-promoting inflammation, deregulating cellular energetics, evading growth suppressors, and avoiding immune destruction. NNA: 1-(N-methyl-N-nitrosamino)-1-(3-pyridinyl)-4-butanal; NNK: 4-(methylnitrosamino)-4-(3-pyridyl)-butanal; NNN: 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone; PAHs: Polycyclic aromatic hydrocarbons; ROS: Reactive oxygen species; TSNAs: Tobacco-specific nitrosamines; VOCs: Volatile organic compounds.