HIF1A and lung adenocarcinoma: In A549 lung adenocarcinoma cells exposed to cadmium, HIF1α has been shown to upregulate the expression level of the intracellular domain (ICD) but not the transmembrane subunit (NTM) of NOTCH1, and the regulation is independent of the HIF1α transcriptional activity (Fujiki et al., 2017).