The impact factor was devised by Eugene Garfield, the founder of the Institute for Scientific Information (ISI), now part of Thomson Reuters. Impact factors are calculated yearly for those journals that are indexed in Thomson Reuter's Journal Citation Reports.
The following are the Impact Factors for some most cited scientific journals in 2007:
Abbreviated Journal Title (Impact Factor)
CA-CANCER J CLIN (69.026)
NEW ENGL J MED (52.589)
ANNU REV IMMUNOL (47.981)
REV MOD PHYS (38.403)
NAT REV MOL CELL BIO (31.921)
ANNU REV BIOCHEM (31.19)
CELL (29.887)
PHYSIOL REV (29.6)
NAT REV CANCER (29.19)
NATURE (28.751)
LANCET (28.638)
NAT REV IMMUNOL (28.3)
NAT MED (26.382)
SCIENCE (26.372)
NAT IMMUNOL (26.218)
ANNU REV NEUROSCI (26.077)
NAT GENET (25.556)
JAMA-J AM MED ASSOC (25.547)
NAT REV NEUROSCI (24.52)
CANCER CELL (23.858)
ANNU REV CELL DEV BI (23.545)
NAT REV DRUG DISCOV (23.308)
NAT BIOTECHNOL 22.848
CHEM REV 22.757
NAT REV GENET 22.399
ANNU REV PHARMACOL 21.696
PROG MATER SCI 20.846
ANNU REV ASTRON ASTR 20.29
PHYS REP 20.263
NAT MATER 19.782
IMMUNITY 19.266
ANNU REV PHYSIOL 18.875
PHARMACOL REV 18.823
ANNU REV PLANT BIOL 18.712
ENDOCR REV 18.493
ANNU REV GENET 18.302
ANNU REV BIOPH BIOM 17.757
NAT CELL BIOL 17.623
BEHAV BRAIN SCI 17.462
CELL METAB 17.148
J CLIN INVEST 16.915
B AM MUS NAT HIST 16.385
ACCOUNTS CHEM RES 16.214
ARCH GEN PSYCHIAT 15.976
CLIN MICROBIOL REV 15.764
J NATL CANCER I 15.678
NAT NEUROSCI 15.664
J EXP MED 15.612
ANN INTERN MED 15.516
J CLIN ONCOL 15.484
NAT METHODS 15.478
TRENDS BIOCHEM SCI 14.994
NAT REV MICROBIOL 14.959
NAT NANOTECHNOL 14.917
TRENDS ECOL EVOL 14.797
GENE DEV 14.795
NAT PHYS 14.677
MICROBIOL MOL BIOL R 14.629
MAT SCI ENG R 14.4
ANNU REV MICROBIOL 14.362
NAT CHEM BIOL 13.683
TRENDS CELL BIOL 13.527
PLOS BIOL 13.501
CURR OPIN CELL BIOL 13.444
ANNU REV MED 13.415
NEURON 13.41
ANNU REV PSYCHOL 13.4
MOL CELL 13.156
CHEM SOC REV 13.082
ANNU REV NUCL PART S 12.885
PROG POLYM SCI 12.809
CIRCULATION 12.755
PLOS MED 12.601
TRENDS NEUROSCI 12.479
DEV CELL 12.436
LANCET ONCOL 12.247
LANCET INFECT DIS 12.058
ALDRICHIM ACTA 11.929
SURF SCI REP 11.923
CYTOKINE GROWTH F R 11.816
GASTROENTEROLOGY 11.673
ANNU REV BIOMED ENG 11.567
REP PROG PHYS 11.366
GENOME RES 11.224
PROG LIPID RES 11.194
AM J HUM GENET 11.092
NAT STRUCT MOL BIOL 11.085
J AM COLL CARDIOL 11.054
MOL PHARM 11.03
PSYCHOL BULL 10.905
MOL PSYCHIATR 10.9
BLOOD 10.896
MASS SPECTROM REV 10.896
ANNU REV PHYTOPATHOL 10.778
HEPATOLOGY 10.734
ANNU REV GENOM HUM G 10.722
ANNU REV ENTOMOL 10.68
CURR BIOL 10.539
IMMUNOL REV 10.536
PROG NEUROBIOL 10.467
ANNU REV ECOL EVOL S 10.34
LANCET NEUROL 10.169
CURR OPIN GENET DEV 10.15
CURR OPIN STRUC BIOL 10.15
ANGEW CHEM INT EDIT 10.031
GUT 10.015
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