There are 11 ITPA variants that have been reported (Sakamoto et al., 2020), and the two most common SNPs are 94C > A as well as IVS2 + 21A > C. Several studies have examined the role of these two variants in the ITPA gene with 6-MP metabolism, as well as adverse drug reactions including hepatotoxicity, flu-like symptoms, arthralgia, and pancreatitis (Arenas et al., 2007; Zabala-Fernandez et al., 2011; Wroblova et al., 2012) with promising results. The gene discussed is ITPA; the disease is pancreatitis.