Identifier types that can be used for a physical entity search:

3dmet
amaze
aracyc
arrayexpress
beilstein
bigg
bind
bindingdb
biocarta
biogrid
biomodels
brenda-compound
cas
cazy
ccsd
chebi
chembl
chemspider
corum
cosmic
dip
disprot
dpd
drugbank
ec
ecocyc
ehmn
embl
emdb
ensembl
entrez
entrez-gene
entrez-gi
genatlas
genbank
genbank indentifier
genbank_nucl_gi
genbank_protein_gi
genecards
glycomedb
go
het
hgnc-id
hgnc-symbol
hmdb
hprd
huge
humancyc
imex
innatedb
inoh
intact
interpro
ipi
ipr
jcggdb
kegg
kegg glycan
kegg-glycan
knapsack
ligandbox
lipid_maps
lipidbank
lipidmaps
locuslink
matrixdb
mdl
merck index
metabolights
mgd
mim
mint
mips
mirbase
mmdb
moped
mpidb
ncbi nucleotide
nci
ndcd
netpath
nikkaji
omim
panther
pdb
pdb-ccd
pdbe
pdbsum
pfam
pharmgkb
phosphosite
phosphositeplus
phylomedb
pid
pid-gene
pig
pin
pride
prints
prosite
proteinmodelportal
proteomexchange
psi-mi
pubchem
pubchem-compound
pubchem-substance
pubmed
rcsb pdb
reactome
refseq
smart
smpdb
smr
spike
string
superdrug
tair
ttd
ucsc
um-bbd-cpd
unigene
uniparc
uniprot
uniprot knowledge base
uniprotkb
vega
wikipathways
wwpdb