TACR1 and myeloid leukemia: SP and NK-1R immunoreactivity was also studied in AML (HL-60, KG-1α, NB4) and chronic (K562) myeloid leukemia cells: all myeloid leukemia cell lines showed a moderate-strong immunoreactivity for both SP and the NK-1R, but in healthy subjects no immunoreactivity was found for both markers (Table 1) [1].