We found that RAB4A, RAB5A, RAB7A, RILP, LAMP-1, and ATP6V1G1 proteins were significantly downregulated in A2780 CIS chemoresistant cells (Fig. 1B, C) allowing to hypothesize the presence in these cells of a dysfunctional endocytic pathway. Here, RAB4A is linked to in situ carcinoma.