Using atomic force microscopy, Wyss and colleagues found that the Young’s modulus of healthy rat and mouse glomeruli is ~2.5 kPa, and demonstrated that at an early stage of injury in Col4a3(-/-) mice (Alport model) and Tg26HIV/nl mice (HIV-associated nephropathy model), the glomeruli were significantly softer than normal [52]. This evidence concerns the gene COL4A3 and HIV-associated nephropathy.