KCNMA1 and preeclampsia: 2004), and that the BK gene occurs within a chromosome region gene cluster containing a gene (STOX1) associated with preeclampsia (van Dijk et al. 2005). Such imprinting in a (+/−)Kcnma1 embryo could lead to loss of BK function when the maternal allele is null, but often paternal imprinting in the placenta does not show complete repression (Wagschal and Feil 2006). Stress‐induced alterations of imprinting might be a part of the mechanism that selectively disadvantages het mice (Table 3B, Fig. 5).