tokens: Culture of HL60 cells in 5 x 10 ( -7 ) M 9-cis RA together with a wide range of concentrations of D3 resulted in promotion of neutrophil differentiation at 10 ( -15 ) -10 ( -12 ) D3 , a failure to differentiate and apoptosis at 10 ( -11 ) -10 ( -10 ) M D3 , followed by co-operativity between 9-cis RA and 5 x 10 ( -9 ) M D3 in inducing monocyte differentiation in the absence of neutrophil differentiation .