Mollapour is widely recognized for his research on post-translation regulation of the molecular chaperone Heat shock protein-90 (Hsp90) and co-chaperones in cancer. His work demonstrated how reversible biochemical reactions can become directional and ordered, and in general, how a house-keeping machine (Hsp90) can be modulated through signaling inputs. Mollapour’s finding on post-translational modifications of the Hsp90 chaperone machinery has also explained the reasons for tumors sensitivity and selectivity towards the Hsp90 inhibitors.