This document specifies, prior to any data analysis, a test of a single directional hypothesis: that the abundance-weighted P1 fraction of the expressed proteome is higher in tumour than in matched normal tissue. The prediction is a reframing of the metabolic-cost convergence reported by Zhang et al. (2022) into the Perez P1/P2 partition, and nothing more. The test makes no use of the Coates Quartic, the Z/20 cyclic structure, the−3π/10 codon invariant, or any claim that the partition is a mechanism of oncogenesis. It tests composition, full stop. The statistic, null model, confound controls, and decision rule are frozen below and deposited before the analysis pipeline is run, so the DOI time stamp establishes the prediction as prior to data observation