To celebrate the 100th anniversary of the Nencki Institute foundation, a special issue of KOSMOS [67(1)] "Cytoskeleton and cell motility" was prepared under the edition of Hanna Fabczak, Maria Jolanta Rędowicz and Dorota Włoga. The issue contains 16 review articles written by the Institute scientists and alumni, as well as a historical draft on the studies within the issue research field performed in the Institute (authored by M.J. Redowicz and Leszek Kuźnicki), It also contains a translation (made by Stanisław Fabczak) of the chapter of the monography "Biochemistry in the Institute of Experimental Medicine. 1890-2015" describing activities of Marceli Nencki in Sankt-Petersburg (1890-1901) which was published in 2015 on the 125th anniversary of this Institute.