working with php if statements

I have the following php if statement:

        while ($row_cats=mysqli_fetch_array($run_cats)){
            $crs_sub1 = $row_cats['course_subc1'];
                            $crs_sub2 = $row_cats['course_subc2'];

            $crs_sub3 = $row_cats['course_subc3'];

            $crs_sub4 = $row_cats['course_subc4'];

            $crs_sub5 = $row_cats['course_subc5'];

                  $numberIncrease = 0;


                if (($crs_sub1 == "") && (!= $crs_sub2) && (!= $crs_sub3) && (!= $crs_sub4) && (!= $crs_sub5)){

where theres a problem in how the if statement is worded out. The error i get is the following:

Parse error: syntax error, unexpected '!=' (T_IS_NOT_EQUAL) 

for any clarification or explanation, let me know