<prompt> Diffuse proliferative glomerulonephritis, in Lupus nephritis falls under -Class IIClass IIIClass IVClass V  <response>: Robbins basic pathology 9th edition page no 128,Heading Morphologybox Diffuse lupus nephritis class4 is the most serious form of renal lesions in SLE and is also the most commonly encountered in renal biopsies, occuring in35to65of patients. It is distinguished from focal lupus nephritis class3 by involvement of half or more of glomeruli. 