The supplemental figures only include experiments that reproduce previously published work or are not absolutely necessary to support the major and most novel findings of the paper.
Since this paper is primarily studying IFITM localization and clustering at endosomes/lysosomes it should reference studies in which endocytic localization motifs of the IFITMs were identified and characterized (Jia, Cell Microbiol, 2014; Chesarino, JBC, 2014; Li, JBC, 2015) Line 65 states that subsequent studies have failed to confirm an association between SNP rs12252 and severe influenza.