This is the ValueSet that contains all the codes in Antineoplastic and immunostimulating agents (http://hl7.eu/fhir/ig/pcsp/ValueSet/drugsAtc-eu-pcsp) and Antineoplastic and immunostimulating agents (http://hl7.eu/fhir/ig/pcsp/ValueSet/drugsAtc-eu-pcsp). E.g. what you have to deal with if you get resources containing codes in either of them