OpenTargets Get Target Cancer Hallmarks

Retrieve cancer hallmarks annotation for a target by Ensembl gene ID (from the COSMIC Cancer Gene Census / Hanahan-Weinberg hallmarks). Returns cancerHallmarks (each with hallmark label, impact = 'promotes' or 'suppresses', and a mechanistic description with PMID) plus role-in-cancer attributes (name + description). Use to summarise a target's oncogenic mechanisms.