INS and neoplasm: Considering that tumor cells demonstrate abnormal glucose uptake to survive and proliferate (McTiernan, 2008; Ramanujan, 2015) and that insulin is a growth factor that can induce tumor cell proliferation (McTiernan, 2008; Arcidiacono et al., 2012; Brown et al., 2012; Kang et al., 2016; Adraskela et al., 2017), these factors likely influence tumor growth and metastasis in Walker 256 tumor-bearing adult (90 days old) rats.