SMARCA4 and mucinous adenocarcinoma: In addition, all cases in the variant group retained SMARCA4 expression, but in the non-mucinous group, loss of SMARCA4 was detected in 3 of the 15 cases (20%), much more frequently than in HNF4α-negative non-mucinous adenocarcinomas (3/208, 1.4%) (Fig. 2a and Table 1).