IL1A and Buschke-Ollendorff syndrome: Interestingly, a non–statistically significant trend towards an increase in IL‐1α concentration in BOS culture negative BAL compared to non‐BOS culture negative BAL (p = 0.07) was seen suggesting that, apart from bacterial or fungal infection, other factors driving IL‐1α release may be implicated in BOS (Figure 3A).