Zeke Simpson is a "grandfather" of Abe Simpson. Abe's real grandfather is "Old Tut" Simpson, as his whole story about Christmas in "A Trip to Simpsons Mountain" is obviously one of his false stories.
In addition to the immediate relatives listed to the right, he is related to these people:
Grandchildren: Abraham Simpson, Jr., Luke Simpson, Jason Simpson, Leroy Simpson, Tori-Mae Simpson, Rube Ella Simpson and Lisa Marie Simpson
Great-grandchildren: Homer Simpson, Herbert Powell and Abbie
Great-great-grandchildren: Lisa Simpson, Bart Simpson and Maggie Simpson