NCIt definition : Not known, observed, recorded; or reported as unknown by the data contributor.;
Alternative definition : CDISC: Not known, not observed, not recorded, or refused. (NCI); PCDC: Reported as unknown by the data contributor.; FDA: Not known, not observed, not recorded, or refused.; ACC/AHA: A proper value is applicable but not known.;
NCIt note : Used for Cancer Activities Coding when cancer activity is not specified.;