Deignan won the 2016 edition of the race after accelerating clear of Katarzyna Niewiadoma and Emma Johansson on the final climb to the finish in Siena to go one better than her placing in 2015.
Alongside Deignan in Boels Dolmans colours will be Megan Guarnier, the winner of the 2015 race, Amalie Diderikson, the world champion, and new recruit Anna Van der Breggen.
Also boasting potential winners in their squads are WM3 Pro Cycling, with Niewiadoma and Marianne Vos, Orica-Scott, with Annemiek Van Vleuten, Canyon-SRAM, with Pauline Ferrand-Prevot, and Team Sunweb, with the recent Omloop Het Nieuwsblad winner Lucinda Brand.
The women’s race will take in similar white gravel roads to the men’s race and start and finish in Siena, but will be run over 127km rather than 175km.
This is the opening race in the Women’s WorldTour, which is in its second year in existence after replacing the Women’s World Cup in 2016.