A study by Hillian et al. [16] identified three polymorphic variants of the IL8 gene that are associated with the severity of lung disease in CF: rs4073 (IL8 −251 T/A), rs2227306 (IL8 781 C/T), and rs2227307 (IL8 396 T/G) [16]. This evidence concerns the gene CXCL8 and cystic fibrosis.