Lyp protein expression in lymphoid and myeloid cell lines. Lyp was immunoprecipitated from cell lines (10⁷cells) and blotted with Lyp antibodies. A protein band of 105 kD corresponding to LyP1 could be detected in Jurkat, Daudi, Ramos, A1, and G2 cells, whereas U937 and K562 do not appear to have detectable amounts of Lyp. (PB), preimmune serum control.