 According to Houbraken he was one of a group of teachers of Nicolaes Berchem, along with Berchem's father Pieter Klaaze (a "gemeen" or common painter), Jan van Goijen, Klaas Mojaart, Pieter Fransze Grebber, and Berchem's cousin Giov.Babtist Weeninx.Jan Wils' daughter married Berchem, and when she heard nothing from his studio upstairs, she would bang on the ceiling with a mop to wake him up, assuming he had fallen asleep at his easel.