The Wnt-3a-imposed abrogation of differentiated response to lactogenic hormones was mitigated in pBabeSFRP-4-infected Line 31E cells. Using Northern blot methods, the expression of β-casein was investigated after stimulation of cultures with Wnt-3a and/or different combinations of growth factors and lactogenic hormones. Lines 31E +30F co-cultures containing either pBabeVector or pBabeSFRP-4-infected Line 31E cells were compared. Most notable is that Wnt-3a is capable of completely suppressing the differentiation to β-casein expression stimulated by dexamethazone-insulin-prolactin (DIP). However, co-cultures containing Line 31E cells infected with SFRP-4 show definite β-casein induction in spite of Wnt-3a treatment. Ribosomal RNA was stained with acridine orange as a loading control.