The atp1b1a gene is essential (green arrows) for the maintenance of a healthy epidermis (by maintaining the cell polarity and cell adhesion), and for the proper functioning of the heart and pronephros (the larval kidney). The atp1b1a function is necessary to suppress the predisposition of the epidermis to malignancy and to prevent hypotonic stress by facilitating normal kidney function (red inhibitory arrows). In the absence of atp1b1a function, the predisposed epidermis undergoes a malignant transformation as a consequence of the PI3K-AKT-mTORC1-NFκB pathway being activated by the hypotonic stress caused by a dysfunctional pronephros.