(A) Northern blot analysis of CEV14 in several kinds of leukemia cell lines. Poly(A)⁺ RNA (3 μg) was isolated from the following cell lines: HL-60, promyelocytic leukemia cell line; U937, monocytic leukemia cell line; K562, erythroleukemia cell line; MEG-A2, megakaryoblastic cell line. (B) Twenty micrograms of HL-60 poly(A)⁺ RNA was subjected to Northern blot analysis to detect minor transcripts. Probe C1 detects three major transcripts and several minor transcripts as indicated with an arrow.