ACE and diabetes mellitus: On 11 March 2020, a letter published online in The Lancet highlighted that patients with comorbidities (diabetes or hypertension) who are treated with angiotensin-converting enzyme (ACE) inhibitors and angiotensin II type-I receptor blockers (ARBs) experience substantially increased expression of ACE2, the viral receptor for SARS-CoV-2 (Fig. 1).