Abstract: The present invention refers to the use of a small molecule to inhibit cellular hallmarks of aging, with therapeutic impact in aging-associated diseases and progeroid syndromes. The present invention discloses that defective mitotic mechanisms contribute to age-associated chromosomal instability (CIN) and to cell senescence. In particular, the present invention discloses that dysfunction of microtubule dynamics arising with age due to decreased MT-depolymerizing kinesin-13 activity, mildly perturbs genomic stability and contributes to the generation of fully senescent cells. Importantly, chromosomal stability in old-aged cells is restored upon the use of a small molecule to enhance MT-depolymerizing kinesin-13. Therefore, the present invention refers to 4-Pyrrolidin-1-Yl-5-P-Tolyl-Thieno[2,3-D]Pyrimidine substances or compositions, and any of its derivatives, for use in the treatment of ageing associated diseases, through restored chromosomal stability and inhibition of the phenotypes of cellular senescence.