This Forum issue "Heme Oxygenase" (HO) includes original research articles and reviews that are aimed at understanding the role of HO-1 in several pathophysiological conditions, specially addressing those involving inflammation and oxidative damage. Overall, the seven contributions of this Forum highlight the dual role that HO-1 displays in cells and tissues, and address the molecular and cellular mechanisms through which HO-1 participates in the pathophysiology of the metabolic syndrome, obesity, cancer, and neurodegenerative, neurodevelopmental, and inflammatory bowel diseases. Indeed, one of the reviews thoroughly describes evidence of the anti-inflammatory properties of HO-1 in gut homeostasis, with potential to attenuate inflammatory bowel diseases. Three other reviews show the mostly beneficial effect of HO-1 expression in the attenuation of metabolic syndrome, obesity, cardiovascular disease, and diabetic cardiomyopathy. Contrariwise, one of the original articles show the overexpression of HO-1 in astroglia, models neurodegenerative (Parkinson-like) or neurodevelopmental (Schizophrenia-like) behaviors in mice, depending on the timing of expression of HO-1 during lifespan. The other original research communication demonstrates the role of HO-1 on the tropism of prostate cancer cells to bone, thus showing the involvement of this protein in the communication between bone and cancer cells. Finally, the Forum issue includes a review that elaborates on the classic and ultimate knowledge of HO-1 transcriptional regulation as well as the mechanisms of alternative splicing and post-transcriptional regulation of Hmox1 gene expression that have been little explored. Antioxid. Redox Signal. 32, 1239-1242.