CHOP expression is decreased in thapsigargin-treated RASF. Thapsigargin (5 μM) was added for 0, 0.5, 1, 2, 4 and 8 h and SDS-PAGE and immunoblotting was performed with anti-GRP78, GRP94, CHOP, p21, p53 or Bax antibody (a: upper). The expression of GRP78 and CHOP was quantified (a: lower). OASF and RASF were treated with thapsigargin (5 μM) for 0, 12, 36, 48 and 60 h. After incubation, total protein was extracted. SDS-PAGE was performed and GRP78 and CHOP expression was analyzed (b: upper). The expression of CHOP was quantified (b: lower) *P < 0.05, versus non-treated OASF. #P < 0.05, versus OASF with same treatments.