FH and atypical hemolytic-uremic syndrome: The importance of FH as a complement regulator and conveyor of host protection is highlighted in cases where its function is perturbed leading to a number of non-ocular diseases, for example in the kidney conditions including atypical hemolytic uremic syndrome (aHUS) and Membranoproliferative Glomerulonephritis Type II (MPGNII—also referred to as dense deposit disease).