CX3CL1 and Alzheimer disease: Subsequent analysis of Fan et al., was carried out using transgenic Tg mice overexpressing CX3CLK1 and a PS19 AD mouse model, confirming that FKN enhances neurogenesis via Smad signalling and showing that the CX3CL1ct reduces neuronal loss and improves cognitive function, as defined by learning and memory process, in AD mice [60].