Frozen sections of normal (left) and Lamb2–/–(right) kidneys were stained for laminin β2 (Lamβ2; A and B), α5 (C and D), α1 (E and F), α2 (G and H), and α3β3γ2 (LM-332; I and J). Normal GBM contains laminin β2 and α5 (and γ1; data not shown); laminin α5 was decreased in Lamb2–/–GBM. Normal glomeruli exhibit variable mesangial staining for laminin α1 and α2 but not LM-332; however, all were detected ectopically in Lamb2–/– GBM. Original magnification, ×600.