Table 2.

The 30 most frequent relationship types and entities modified by genes, drugs or phenotypes. Numbers correspond to their frequency of occurrence in 41,134 raw relationships extracted from 17,396,436 MEDLINE abstracts. Entities can be composed of one or several words.

relationship types	entities modified by
	genes	drugs	phenotypes
2538 associate	1237 gene	267 metabolism	304 cell
1017 increase	1000 inhibitor	229 activity	114 line
985 inhibit	935 polymorphism	226 administration	101 patient
825 induce	775 expression	213 treatment	71 risk
763 metabolize	773 activity	207 effect	35 tissue
666 involve	689 mutation	205 inhibitor	34 specimen
643 reduce	685 genotype	146 dose	33 case
547 catalyze	393 inhibition	137 concentration	27 treatment
515 cause	329 level	104 level	26 rate
509 affect	245 gene_mutation	103 substrate	26 effect
490 decrease	232 gene_polymorphism	90 clearance	26 breast=cancer
433 show	227 allele	88 antagonist	22 incidence
428 express	162 variant	84 channel	21 factor
392 relate	156 enzyme	75 inhibition	21 resistance
392 use	138 mrna	73 responsible	20 sample
387 correlate	125 protein	72 hydroxylation	18 model
385 influence	83 channel	70 enzyme	16 exposure
355 determine	81 isoform	67 oxidation	15 type
354 contribute	78 effect	65 gene	15 development
319 factor	77 isozyme	63 formation	15 group
318 mediate	76 cell	62 blocker	14 %
317 had	73 deficiency	60 metabolite	14 activity
301 found	71 overexpression	57 dependent	14 mellitus
299 measure	67 substrate	52 exposure	13 gene
287 investigate	67 induction	46 ratio	13 cause
284 result	63 gene_expression	45 consumption	13 presence
281 studied	59 c677t	44 due	13 all
280 detect	58 inhibitor_use	43 drug	13 level
274 association	57 gene_allele	40 response	12 severity
274 have	55 content	38 bioavailability	12 study