Here you can find numbers and summary statistics about the entities like proteins and proteoforms in Reactome^[1] as well as their mapping to reactions and pathways.

The numbers correspond to the mapping in PathwayMatcher 1.9.1 and Reactome v68.

The cypher queries to replicate this numbers are here.

• Number of UniProt^[1] accessions related to human PhysicalEntity objects: 10825

• Number of human PhysicalEntity objects related to a UniProt accession distinguishing between isoform sequences: 11000

• Number of proteins with an isoform other than the default: 265

• Number of proteins with more than one isoform: 64

• Reactions per protein:

Min	Average	Max
0	7.327	318

• Reactions per protein with at least one annotated reaction:

Min	Average	Max
1	7.677	318

• Pathways per protein:

Min	Average	Max
0	8.454	293

• For proteins with at least one pathway annotated:

Min	Average	Max
1	8.858	293

• Human proteins participating in the highest number of pathways in Reactome:

Protein Accession	Gene	Protein name	Reactions Mapped	Pathways Mapped
P62979	RPS27A	Ubiquitin-40S ribosomal protein S27a	309	293
P62987	UBA52	Ubiquitin-60S ribosomal protein L40	302	289
P0CG47	UBB	Polyubiquitin-B	282	271
P0CG48	UBC	Polyubiquitin-C	282	271
P28482	MAPK1	Mitogen-activated protein kinase 1	71	134
P27361	MAPK3	Mitogen-activated protein kinase 3	67	127
P0DP23	CALM1	Calmodulin-1	79	122
Q07889	SOS1	Son of sevenless homolog 1	123	109
P67775	PPP2CA	Serine/threonine-protein phosphatase 2A catalytic subunit alpha	61	107
P27986	PIK3R1	Phosphatidylinositol 3-kinase regulatory subunit alpha	111	106

Note that the Reactions Mapped column shows the number of reactions that are part of the mapped pathways. A protein may participate in a reaction that was not assigned to a pathway. A reaction can also be part of multiple pathways.

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• Total number of proteoforms: 13978

• Proteoforms with at least one post translational modification: 3137 (22.44% of the proteoforms)

• PTM sets per protein:

min	average	max
1	2.26	316

• Reactions per proteoform:

min	average	max
0	6.298	316

• Reactions per proteoform with at least one reaction annotated:

min	average	max
1	6.666	316

• Pathways per proteoform:

min	average	max
0	7.758	292

• Pathways per proteoform with at least one pathway annotated:

min	average	max
1	8.215	292

• Human proteoforms participating in the highest number of pathways in Reactome:

Protein Accession	Gene	Protein name	PTMs	Reactions Mapped	Pathways Mapped
P28482	MAPK1	Mitogen-activated protein kinase 1	[00047:185, 00048:187]	49	126
P27361	MAPK3	Mitogen-activated protein kinase 3	[00047:202, 00048:204]	46	117
P31749	AKT1	RAC-alpha serine/threonine-protein kinase ecNumber2.7.11.1/ecNumber	[00046:473, 00047:308]	53	86
P16220	CREB1	Cyclic AMP-responsive element-binding protein 1	[00046:133]	15	78
P31751	AKT2	RAC-beta serine/threonine-protein kinase ecNumber2.7.11.1/ecNumber	[00046:474, 00047:309]	34	75
Q9GZV9	FGF23	Fibroblast growth factor 23	[00164:178]	152	68
Q16539	MAPK14	Mitogen-activated protein kinase 14	[00047:180, 00048:182]	17	65
P12931	SRC	Proto-oncogene tyrosine-protein kinase Src	[00048:419, 00068:2]	44	59
P19174	PLCG1	1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase gamma-1 ecNumber3.1.4.11/ecNumber	[00048:472, 00048:771, 00048:783, 00048:1253]	39	59
Q9Y243	AKT3	RAC-gamma serine/threonine-protein kinase	[00046:472, 00047:305]	26	59

[1] Fabregat, A. et al. The Reactome Pathway Knowledgebase. Nucleic acids research 46, D649-d655, doi:10.1093/nar/gkx1132 (2018).
[2] The UniProt Consortium, UniProt: the universal protein knowledgebase. NAR (2017)