Immortalized progenitor cells were plated and grown in DMEM/H medium supplemented with 10% FBS (referred as day 0). For adipocyte differentiation, cell were grown for 6 days until reaching confluence (day 6), and then treated with the adipogenic induction medium as described above for 12 days (day 18). To further stimulate thermogenic program, fully differentiated cells were incubated with 10μM forskolin or 1 μM norepinephrine for 4 h. For BMPs and FGF21 pre-treatment, recombinant BMP7 (3.3 nM), BMP8 (3.3 nM), or FGF21 (50 nM) were added to undifferentiated cells in medium containing insulin (0.5 μM), T3 (2 nM) and 2% FBS for 6 days followed by adipogenic induction for 12 days. For BMPs and FGF21 post-treatment, fully differentiated adipocytes at day 18 were treated with recombinant BMP7 (3.3 nM), BMP8 (3.3 nM), or FGF21 (50 nM) in medium containing insulin (0.5 μM), T3 (2 nM) and 2% FBS for 2 days. We routinely check for mycoplasma contamination and all the cells used in this study are free of mycoplasma.