HMOX1 and non-small cell lung carcinoma: NCI-Nrf2 cells were transfected with siRNA against HO-1 (Fig. S2), which led to a partial downregulation of TP expression in both Nrf2-overexpressing cells and control cells transduced with empty vector (NCI-EV) (Fig. 2A), implying that HO-1 plays a role in the regulation of TP in NSCLC, yet its involvement in the effect of Nrf2 is minor.