Webometrics have announced that 16 Greek University professors are amongst the world’s most Highly Cited Researchers (h>100). Specifically, there are eight professors from the National and Kapodistrian University of Athens, six from the National Technical University of Athens (NTUA), two from the National Research Center, Demokritos, as well as one from University of Ioannina. First ranked worldwide is Johns Hopkins University's Neuroscience Professor Solomon H. Snyder, with h-index 279 and referenced 357, 238 times. More specifically, the eight Professors and Researchers of the University of Athens with the most significant international research work in Medicine, are Georgios Hrousos ( h-index 182 and cited 137,377 times), the rector of the Meletios Athanasios Dimopoulos Foundation (h-index 120 and 64,696 references), Charalambos Moutsopoulos ( h-index 107 and 46,819 references), Marinos Dalakas (h-index 106 and 41,693 references), Christodoulos Stefanadis (h-index 105 and 60,846 references) and Physics Paraskevas Sfikas ( h-index 172 and 136,823 references), Christina Kourkoumeli (h-index 164 and 129,757 citations) and Eustathios Stuliaris (h-index 101 and 46,605 citations). The professors from the National Technical University of Athens are: Georgios Tsipolitis (166 h-index and 122,232 references), Manolis Drys (163 h-index and 127,852 references), Stavros Maltezos (161 h-index and 118,813 references), Theodoros Alexopoulos (159 h -index and 112.303 references), Evangelos Gazis (154 h-index and 156,763 references) and Konstantinos Kousouris (145 h-index and 88,345 references).