To study the expression of JWA protein and heat shock protein (Hsp70), and to explore these relationship and the possible mechanism of JWA gene involved in induced differentiation and heat stress (42 degrees C) of K562 cells.The models of differentiation and heat stress of K562 cells were established. Western blot was used for detecting expressed proteins of JWA gene, Hsp70, heat shock factor (HSF1 and HSF2).(1) Under the condition of differentiations induced by TPA (100 ng/ml), hemin (3 x 10(-5) mol/L), Ara-C (80 ng/ml), adriamycin (4 x 10(-8) mol/L), ATRA (1 x 10(-6) mol/L) and As(2)O(3) (1 x 10(-6) mol/L) for 48 h respectively, the expression of JWA protein and Hsp70 were more significantly increased than control; the level of HSF2 protein was increased by inductions of hemin, Ara-C and adriamycin, respectively. (2) After heat exposure to 42 degrees C for 10, 20, 30, 45, 60, 90 min, and heat exposure to 39 degrees C, 42 degrees C, 45 degrees C, the trend of changing in expression of Hsp70 was similar to that of JWA protein, and HSF1 was expressed in earlier stage.The expression of JWA protein and Hsp70 were upregulated in induced differentiation and in heat stress, and the change of expression of JWA protein were similar to that of Hsp70, but the intracellular transduction signal pathways involved may be various. JWA might not be specifically related with both HSF1 and HSF2.