In 2015, the 7-year-old chronic asthmatic mentioned at the beginning of the article has some genotype information known at the time of his presentation - it was collected at a pulmonary clinic visit the previous year after an ICU admission. Much like a history of a smoker at home, his parent may report that he has the "steroid gene" that you know means he carries a haplotype in the gene for one of his glucocorticoid receptors that makes him less sensitive to glucocorticoid treatment and thus requires higher doses and longer treatment. You adjust your therapy accordingly. This patient scenario becomes closer to reality each year as genomic technologies rapidly mature. The role of environment in the asthma epidemic cannot be discounted - its role is clear and important. However, despite the long-held knowledge that genes are important in asthma as well, the study of genetics in asthma had been limited by the lack of a means by which to examine it. Relatively, little had changed since Sir William Osler wrote about asthma 100 years ago. Now, we are on the verge of significant change.