Registration is open for the 33rd annual Boston Marathon Jimmy Fund Walk. This year’s event will be virtual. Participants are encouraged to “Walk Your Way” from wherever they are most comfortable — for example, in the neighborhood, on a favorite trail or on a treadmill — on Sunday, Oct. 3. Walkers must commit to raising at least $100 ($25 for those under 18). The event raises funds for cancer care and research at Dana-Farber Cancer Institute. To register or support a walker, visit JimmyFundWalk.org or call 866-531-9255.