Studies based on familial IPF have identified rare genetic variants in genes encoding surfactant proteins, including surfactant protein C (SFTPC) and A2 (SFTPA2), and in several genes linked to telomere function, such asTERT (which encodes for telomerase reverse transcriptase, a component of the telomerase complex responsible for maintaining telomere length47). This evidence concerns the gene SFTPC and idiopathic pulmonary fibrosis.