Hi I am using R 2.0.1 in a MacOs 10.3.7. I am using Siggenes to do SAM analysis. I want to get the genes that are differentially between WT and Cond1, using the two class unpaired data. I have run into this problem where some of my analysis yield only NAs. I have looked in the archives, and there's some mention to this but in previous version of Siggenes. Did anyone had the same problem with the most recent version of Siggenes? Here is a basic description of my data: 1 case where everything is ok, the other where I only get NAs. I can send more detailed information if needed. Thanks for any help. 1) case where everthing went fine argument data for sam: data.frame: 14010 obs. of 9 variables: WT.a : num 10.3 95.6 469.7 416.0 536.3 ... WT.b : num 14 50 917 658 775 ... WT.c : num 50.3 56.5 809.5 525.8 729.4 ... WT.d : num 73.6 15.8 829.7 664.4 1218.0 ... WT.e : num 20.8 25.7 963.2 800.6 836.4 ... Cond1.a: num 20.7 23.6 706.1 568.8 706.3 ... Cond1.b: num 66.0 39.7 842.1 667.5 719.3 ... Cond1.c: num 72.1 51.9 896.5 737.2 868.7 ... Cond1.d: num 28.1 64.8 489.5 607.5 835.0 ... output of sam (slot d) d.statistic: num 0.724 -0.226 -0.513 0.430 -0.308 ... 2) case where I only get NAs argument data for sam: WT.a : num 605 4467 1554 1896 2591 ... WT.b : num 1123 3486 2828 2586 3117 ... WT.c : num 1216 3633 2948 2351 2654 ... WT.d : num 1272 3577 3088 2276 2674 ... WT.e : num 1203 3905 2424 2362 2365 ... Cond2.a: num 1174 2727 2651 1660 2672 ... Cond2.b: num 1173 2425 2512 1512 2361 ... Cond3.c: num 1142 2843 2443 1552 2423 ... Cond4.d: num 1139 3579 2566 1449 2649 ... output of sam (slot d) d.statistic: num [1:14010] NA NA NA NA NA NA NA NA NA NA ...