I discuss two of my research projects on QCD factorization. One project is my on-going thesis work on a three loop calculation of neutral current deep inelastic scattering (DIS) cross sections with heavy quark mass dependence. I will discuss briefly the method to implement the heavy-quark mass dependence in an approximate 3 loop calculation in a general mass factorization scheme, and show challenges and implications of the work. The other project is about non-perturbative contributions in transverse-momentum-dependent (TMD) factorization. I present NNLL/NNLO studies of TMD factorization for Z/Gamma production at hadron colliders and show a fit with D0 measurement. Then I introduce a new study on non-perturbative contributions to semi-inclusive DIS cross sections at a low momentum scale.