In MDA-MB-231 breast cancer cells, HSP reduces glucose uptake by down-regulating glucose transporter 1 (GLUT1) and 4 (GLUT4), inhibits insulin receptor-beta subunit (IR-beta) phosphorylation and Akt, leading to suppressed cell proliferation in response to 5–100 μM concentration [63]. Here, AKT1 is linked to hereditary spastic paraplegia.