I discuss the inclusion of the resummation in the context of the determination of parton distribution functions (PDFs). In particular, I present PDFs fits that are obtained including the resummation of threshold logarithms and high-energy logarithms, leading to a more reliable description of the large- and small-x regions of phase space. Specifically, I show how the PDF fit with small-x resummation provide strong evidence of BFKL dynamics in inclusive HERA data.