When did 3D and organoid culture really start (Fig. 2)? Today’s methods are the product of what started in 1906 with the hanging drop tissue culture technique developed by Ross Harrison (Harrison, 1906). As early as 1900, researchers wanted to recapitulate organogenesis in culture and to do so they began by culturing tissue fragments. In these pioneering experiments, Harrison wanted to study the origin of nerve fibers. He took a fragment of embryo nerve cord and placed it on a drop of lymph on a coverslip, which was inverted and sealed over a hollowed slide (Harrison, 1906). This setting provided an adequate environment for the nerve fibers to grow into the medium. Other researchers further adapted this system to culture tissues of diverse origins for prolonged periods of time (Burrows, 1910; Carrel and Burrows, 1910; Fell, 1972). By 1914, Thomson (1914) defined cultures as “controlled” or “uncontrolled” in reference to the fact that in the former the histological and functional characteristics of the original organ were maintained, whereas in the latter tissue organization and functionality were lost. During the 1920s,
