To address the genetic and molecular mechanisms by which vitamin D can influence asthma, allergic, and autoimmune disease risk, we studied the genetic loci of two chromosome regions of interest: (1) the 17q12-21.1 region, that includes the well-known asthma-associated ORMDL3 gene (Bouzigon et al., 2008; Moffatt et al., 2007), and (2) the 17q21.2 region, that includes the STAT5 gene, known to be extensively associated with autoimmune diseases (Litherland et al., 2005; Kara et al., 2019). Here, ORMDL3 is linked to asthma.