SDC4 and cancer: If RTK stimulates the downstream steps of the PI3K/AKT pathway via complex regulation of PI3K (Corti et al. 2013; Gross and Rotwein 2016; Karczewski et al. 2020; Machiela and Chanock 2015; Schadt et al. 2008); by inhibiting RTK, SDC4-rs1981429 may downregulate the PI3K/AKT pathway, resulting in increased cancer cell survival via inefficient activation of cellular responses to DNA damage and inhibiting apoptosis of precancerous or cancerous cells.