Biological meaning of availability-restricted PPI cascade plateaus

Determine whether restricting each protein–protein interaction cascade to the proteins expressed by a given human cell type produces a biologically meaningful cell-type structure rather than merely rescaling a common interaction signal.

Background

The unrestricted cascade is computed against an interaction-library universe in which every catalogued protein is treated as available. The paper proposes instead to restrict both usable interaction terms and the statistical background to proteins expressed in each cell type, thereby making the cascade output cell-type-specific.

Before the analyses reported in the paper, it was unresolved whether this restriction would reveal genuine biological structure or simply produce quantitative changes in a common network signal. The authors explicitly characterize this as an empirical question and propose testing it using single-cell consensus expression data across human cell types.

References

Whether that restriction produces a map with biologically-meaningful cell-type structure, or merely rescales a common message, is an empirical question that should be tested.

— Molecular architecture of TE-seeded chromosome-naive initiation networks of protein-protein interactions delineates the Human Protein Map of the assembly of multiprotein complexes  (2610.01078 - Glinsky, 1 Oct 2026) in Introduction, paragraph beginning “A second untested assumption concerns the availability of pools of proteins”