Results of a semiquantitative RT-PCR for HOXC5 (left panels) and control gene U1A (right panels) on a serial dilution of total RNA (1, 0.1, 0.01, and 0.001 μg) from a centroblastic/centrocytic (cb/cc) lymphoma (case no. 20), a maltoma (case no. 41), an MF (case no. 4), and an ALCL (case no. 23). PCR results performing 30 cycles (upper panels) and 40 cycles (lower panels) are shown. Note that signals for HOXC5 in the maltoma and ALCL are visible after less PCR cycles and at higher dilutions than those in the cb/cc and the MF. Very weak bands for HOXC5 in the first dilution of cb/cc, the third dilution of maltoma after 30 cycles, and the fourth dilution of the maltoma after 40 cycles are not visible in the figure, but are present on the films.