Varieties of general type, Calabi-Yau varieties and Fano varieties are building blocks of varieties in the sense of birational geometry. It is expected that such varieties satisfy certain finiteness. Birkar recently proved that Fano varieties with bounded singularities belong to finitely many algebraic families (BAB Conjecture). We show that rationally connected klt Calabi-Yau 3-folds form a birationally bounded family. This is a joint work with W. Chen, G. Di Cerbo, C. Jiang, and R. Svaldi.