Heart ventricles were placed in the ice-cold PBS buffer with 1% BSA. After several washes removing blood cells, ventricles were gently cut into small pieces. Tissues were incubated in digestion buffer (0.5 ml HBSS plus 0.26 U/ml Liberase DH [Roche] and 1% sheep serum) for 45 minutes at 37°C while agitating at 750 rpm on an Eppendorf ThermoMixer. Supernatants were collected every 15 min and neutralized with 10% sheep serum, and cells were completely disaggregated by gently pipetting up and down. The dissociated cells were centrifuged at 200 g for 5 min at 4°C and re-suspended in HBSS with 0.05% BSA. The cell suspension (2 ml) was then gently added on top of 2 ml HBSS buffer with 7.5% BSA. After spinning down at 200 g for 5 min at 4°C, the pellet was resuspended in 500 l and filtered through a 35 mm strainer.  Whole kidney marrow cells were isolated as described previously. Briefly, kidneys were collected on ice and homogenized immediately in PBS plus 0.05% BSA by using a 10ml syringe with 18 1/2 G. The dissociated cells were washed twice in PBS plus 0.05% BSA and spun down at 300 g for 5 min at 4°C. Pellets were re-suspended in PBS plus 0.05% BSA and filtered through a 35 mm strainer. Livers were collected on ice and incubated in digestion buffer (0.5 ml HBSS plus 0.13 U/ml Liberase DH [Roche] and 1% sheep serum) at room temperature. The cell lyses was gently stirred with a Spinbar magnetic stirring bar (Bel-Art Products), and the supernatant were collected every 5 minutes. The cell lysate was filtered through a 70 mm strainer and centrifuged at 150 g for 3 min at 4°C. Pellet was resuspended in PBS plus 0.05% BSA and then gently added on top of HBSS buffer with 7.5% BSA. After spinning down at 300 g for 5 min, pellets were washed one more time with PBS plus 0.05% BSA. After centrifuging at 300 g for 5 min, the resuspended cell lyses was filtered through a 35 mm strainer. Pancreatic cells were isolated using the same protocol as liver cells except for the initial spinning down at 300 g for 5 min. All suspended cells were stained with trypan blue and counted using a hemocytometer. Standard library construction protocol using 10x Genomics Chromium Single Cell 3' GEM, Library & Gel Bead Kit v3, and Chromium Single Cell B Chip Kit.