Alexander Jacob Varshavsky (Russian: Александр Яковлевич Варшавский; born 8 November 1946) is a Russian-American biochemist, noted for his discovery of the N-end rule of ubiquitination. A native of Moscow, he is currently researching at Caltech.
Varshavsky provided an original approach to killing cancer cells, proffering the idea of a targeted molecular device that could enter a cell, examine it for DNA deletions specific to cancer and killing it if it meets the right profile. "(It) involves, in a nutshell, the finding of a genuine Achilles' heel of cancer cells, i.e. their potentially vulnerable feature that won't change during tumor progression," said Varshavsky.
The approach termed deletion-specific targeting (DST), employs HDs (homozygous DNA deletions) as the targets of cancer therapy. "In contrast to other attributes of cancer cells, their HDs are immutable markers. If the DST strategy can be implemented in a clinical setting, it may prove to be both curative and free of side effects."
Recipient of the Gairdner Foundation International Award  in 1999, Albert Lasker Award for Basic Medical Research  in 2000, the Wolf Prize in Medicine, the Massry Prize from the Keck School of Medicine, University of Southern California in 2001, and the Louisa Gross Horwitz Prize  from Columbia University in 2001 for his research on ubiquitination.
In 2010, he received the Vilcek Prize in Biomedical Science. The following year, he received the BBVA Foundation Frontiers of Knowledge Award of Biomedicine for his discovery of the mechanisms intervening in protein degradation and their importance in biological systems. His work has implications for the understanding of cancer and immunological and neurodegenerative diseases.
- Who's who in the West: A Biographical Dictionary of Noteworthy Men and Women of the Pacific Coast and the Western States.
- Gairdner Award
- Albert Lasker Award for Basic Medical Research Archived 2015-03-30 at the Wayback Machine
- Wolf Prize in Medicine
- Louisa Gross Horwitz Prize
- "ASBMB News". www.asbmb.org. Retrieved 2015-11-11.
- Breakthrough Prize in Life Sciences 2014
- Albany Medical Center Prize 2014