Engaging in theories of responsibilization, this chapter seeks to demonstrate the often intimate links between responsibilization and biopolitical claims of dependency, blame, helplessness, and culpability, and to show responsibility’s complex relationship with practices of irresponsibilization. Ethnographically, my analysis pivots around an interaction between a radiobiologist and a veteran who participated in British nuclear bomb tests in the Pacific in the 1950s, developments within experimental science that are reconfiguring the biological role of the gene in newly relational ways, and the subsequent translation of this scientific knowledge by nuclear test veterans who contextualize it within the frames of their own grievances...