INS and cancer: Nevertheless, data coming from observational studies are still conflicting and inconclusive, since some authors observe an association between insulin therapy and increased cancer risk (Currie et al., 2009; Tseng, 2019; Vicentini et al., 2022), while others failed to register any association (Pocock and Smeeth, 2009; But et al., 2017; Tan et al., 2017).