Collectively, these four enzymes—LSS, CYP51A1, MSMO1, and DHCR24—cover sequential reactions from the early to the terminal stages of the cholesterol biosynthetic pathway, offering an integrated view of sterol metabolism and suggesting that CaSR signaling may intersect with multiple levels of cholesterol regulation in osteosarcoma cells. The gene discussed is LSS; the disease is osteosarcoma.