Takeuchi M, Hayakawa A, Takagi K, Hiramatsu K, Shimizu Y, Matsumoto S, Hiramatsu T, Ito Y, Kume H, Suzuki R, Yamaki K. Theophylline induces apoptosis of the IL-3 activated eosinophils of patients with bronchial asthma. Apoptosis. 1999 Dec;4(6):461–8. doi: 10.1023/a:1009656527168. PMID: 14634331.