This paper analyses the immunological response of breast cancer patients through the lens of medical semiotics. From this perspective both psychological and physiological symptoms are treated as a set of transitive signs. The symptomatic journey of breast cancer patients was documented through an ethnographic engagement with a breast cancer charity. This journey consists of diagnosis, treatment and remission, where both the physical and psychological trauma maybe irreversible. Equally the genetic disposition of each patient and the variability of the treatment give rise to a plethora of possible immunological responses. The case study organization provided both therapeutic treatment but also sold oncology products to its patients, matching the products’ composition to the specific immunological responses caused by breast cancer treatment, e.g., brittle skins or hair loss, etc. This paper explores how the varied and transient nature of immunological semiosis is identified and commoditized into an economic process. This challenging social context is of interest from a semiotic stand point because it offers a singular paradigm to explain the evolution of signs and symptoms into sales.