Mice deficient for PDGF B exhibit severe renal, cardiovascular, and hematological abnormalities, leading to perinatal death. The study shows that PDGF B is essential for normal kidney development, as glomerular tufts fail to form due to the absence of mesangial cells, replaced by distended capillary loops. Heart and blood vessel dilation, hemorrhages, and anemia are also observed, with PDGF B mutants displaying erythroblastosis, macrocytic anemia, and thrombocytopenia. These findings indicate that PDGF B plays a crucial role in establishing renal and circulatory functions in vivo. The PDGF B gene knockout model revealed that the absence of PDGF B leads to structural and functional defects in the kidney, heart, and blood vessels. The study also highlights the importance of PDGF B in mesangial cell development and function, as well as its role in vascular and cardiac development. The results suggest that PDGF B is involved in the regulation of cell proliferation, migration, and function in various tissues, including the kidney, heart, and blood vessels. The study provides insights into the physiological functions of PDGF B and its importance in embryonic development and organ formation.Mice deficient for PDGF B exhibit severe renal, cardiovascular, and hematological abnormalities, leading to perinatal death. The study shows that PDGF B is essential for normal kidney development, as glomerular tufts fail to form due to the absence of mesangial cells, replaced by distended capillary loops. Heart and blood vessel dilation, hemorrhages, and anemia are also observed, with PDGF B mutants displaying erythroblastosis, macrocytic anemia, and thrombocytopenia. These findings indicate that PDGF B plays a crucial role in establishing renal and circulatory functions in vivo. The PDGF B gene knockout model revealed that the absence of PDGF B leads to structural and functional defects in the kidney, heart, and blood vessels. The study also highlights the importance of PDGF B in mesangial cell development and function, as well as its role in vascular and cardiac development. The results suggest that PDGF B is involved in the regulation of cell proliferation, migration, and function in various tissues, including the kidney, heart, and blood vessels. The study provides insights into the physiological functions of PDGF B and its importance in embryonic development and organ formation.