Omalizumab is a humanised monoclonal antibody against immunoglobulin E (IgE). Several trials have attested to its effectiveness in the treatment of asthma. It has been postulated that because people who live in the inner city are more likely to have multiple and high allergen exposure and are more likely to show allergic sensitisation, they may be more likely to respond to anti-IgE treatment. Now a US trial (N Engl J Med 2011;364 …